Flashcard 1: Slope Formula
Front: m = \frac{y2 - y1}{x2 - x1}
Back:
Purpose: Calculates the steepness (slope) of a line given two points (x1, y1) and (x2, y2).
Variables:
m: slope
(x1, y1): coordinates of the first point
(x2, y2): coordinates of the second point
Note: A positive slope means the line goes up from left to right; a negative slope means it goes down.
Flashcard 2: Slope-Intercept Form of a Linear Equation
Front: y = mx + b
Back:
Purpose: Represents a linear relation, making it easy to identify the slope and y-intercept.
Variables:
y: dependent variable
x: independent variable
m: slope of the line
b: y-intercept (the point where the line crosses the y-axis, i.e., when x=0)
Example: In y = 2x + 3, the slope is 2 and the y-intercept is 3.
Flashcard 3: Standard Form of a Linear Equation
Front: Ax + By + C = 0
Back:
Purpose: Another common way to represent a linear relation. Often used for systems of equations.
Variables:
A, B, C: constants (usually integers, with A typically positive)
x, y: variables
Note: You can convert between standard form and slope-intercept form by rearranging the equation.
Flashcard 4: Distance Formula
Front: d = \sqrt{(x2 - x1)^2 + (y2 - y1)^2}
Back:
Purpose: Calculates the distance between two points (x1, y1) and (x2, y2).
Variables:
d: distance
(x1, y1): coordinates of the first point
(x2, y2): coordinates of the second point
Connection: This formula is derived directly from the Pythagorean theorem.
Flashcard 5: Midpoint Formula
Front: M = \left(\frac{x1 + x2}{2}, \frac{y1 + y2}{2}\right)
Back:
Purpose: Calculates the coordinates of the midpoint of a line segment connecting two points (x1, y1) and (x2, y2).
Variables:
M: midpoint coordinates
(x1, y1): coordinates of the first point
(x2, y2): coordinates of the second point
Note: It's essentially the average of the x-coordinates and the average of the y-coordinates.
Flashcard 6: Standard Form of a Quadratic Equation
Front: y = ax^2 + bx + c
Back:
Purpose: The most common form of a quadratic relation. The graph is a parabola.
Variables:
a, b, c: constants (a \neq 0)
x, y: variables
Note:
If a > 0, the parabola opens upwards.
If a < 0, the parabola opens downwards.
c is the y-intercept.
Flashcard 7: Vertex Form of a Quadratic Equation
Front: y = a(x - h)^2 + k
Back:
Purpose: Easily identifies the vertex of the parabola.
Variables:
(h, k): coordinates of the vertex of the parabola
a: same 'a' value as in standard form, determines direction of opening and vertical stretch/compression.
Note: The axis of symmetry is the vertical line x = h.
Flashcard 8: Factored Form of a Quadratic Equation
Front: y = a(x - r)(x - s)
Back:
Purpose: Easily identifies the x-intercepts (roots/zeros) of the parabola.
Variables:
r and s: the x-intercepts (where the parabola crosses the x-axis, i.e., when y=0)
a: same 'a' value as in standard form.
Note: The x-coordinate of the vertex is the average of the roots: x_v = \frac{r+s}{2}.
Flashcard 9: Quadratic Formula
Front: x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}
Back:
Purpose: Solves for the roots (x-intercepts) of any quadratic equation in the form ax^2 + bx + c = 0.
Variables:
a, b, c: coefficients from the standard form of the quadratic equation.
x: the values of x where the parabola crosses the x-axis.
Note: This formula can always be used, even when factoring is difficult or impossible.
Flashcard 10: Discriminant
Front: \Delta = b^2 - 4ac
Back:
Purpose: Determines the number of real roots (x-intercepts) a quadratic equation has without solving the entire quadratic formula.
Variables:
a, b, c: coefficients from the standard form of the quadratic equation.
Interpretation:
If \Delta > 0: Two distinct real roots.
If \Delta = 0: One real root (a double root).
If \Delta < 0: No real roots (the parabola does not intersect the x-axis).
Flashcard 11: Pythagorean Theorem
Front: a^2 + b^2 = c^2
Back:
Purpose: Relates the lengths of the sides of a right-angled triangle.
Variables:
a, b: lengths of the two shorter sides (legs) of the right triangle.
c: length of the longest side (hypotenuse), opposite the right angle.
Note: Only applies to right triangles!
Flashcard 12: Sine Ratio (SOH)
Front: \sin(\theta) = \frac{\text{Opposite}}{\text{Hypotenuse}}
Back:
Purpose: Relates an angle in a right triangle to the ratio of the length of the side opposite the angle and the hypotenuse.
Variables:
\theta: the angle in question.
"Opposite": length of the side opposite to angle \theta.
"Hypotenuse": length of the side opposite the right angle.
Flashcard 13: Cosine Ratio (CAH)
Front: \cos(\theta) = \frac{\text{Adjacent}}{\text{Hypotenuse}}
Back:
Purpose: Relates an angle in a right triangle to the ratio of the length of the side adjacent to the angle and the hypotenuse.
Variables:
\theta: the angle in question.
"Adjacent": length of the side adjacent to angle \theta (not the hypotenuse).
"Hypotenuse": length of the side opposite the right angle.
Flashcard 14: Tangent Ratio (TOA)
Front: \tan(\theta) = \frac{\text{Opposite}}{\text{Adjacent}}
Back:
Purpose: Relates an angle in a right triangle to the ratio of the length of the side opposite the angle and the side adjacent to the angle.
Variables:
\theta: the angle in question.
"Opposite": length of the side opposite to angle \theta.
"Adjacent": length of the side adjacent to angle \theta (not the hypotenuse).
Flashcard 15: Area of a Rectangle/Square
Front: A = l \times w
Back:
Purpose: Calculates the area of a rectangle or square.
Variables:
A: Area
l: length
w: width
Note: For a square, l=w, so A = s^2 (where s is side length).
Flashcard 16: Area of a Triangle
Front: A = \frac{1}{2}bh
Back:
Purpose: Calculates the area of any triangle.
Variables:
A: Area
b: length of the base
h: perpendicular height from the base to the opposite vertex
Flashcard 17: Area of a Circle
Front: A = \pi r^2
Back:
Purpose: Calculates the area of a circle.
Variables:
A: Area
\pi: pi (approximately 3.14159)
r: radius of the circle
Flashcard 18: Circumference of a Circle
Front: C = 2\pi r or C = \pi d
Back:
Purpose: Calculates the distance around a circle.
Variables:
C: Circumference
\pi: pi
r: radius
d: diameter (d = 2r)
Flashcard 19: Volume of a Prism/Cylinder
Front: V = A_{\text{base}} \times h
Back:
Purpose: Calculates the volume of any prism (e.g., rectangular prism, triangular prism) or cylinder.
Variables:
V: Volume
A_{\text{base}}: Area of the base shape (e.g., l \times w for a rectangular prism, \pi r^2 for a cylinder)
h: height of the prism/cylinder
Flashcard 20: Volume of a Pyramid/Cone
Front: V = \frac{1}{3} A_{\text{base}} \times h
Back:
Purpose: Calculates the volume of any pyramid (e.g., square pyramid, triangular pyramid) or cone.
Variables:
V: Volume
A_{\text{base}}: Area of the base shape (e.g., s^2 for a square pyramid, \pi r^2 for a cone)
h: perpendicular height from the base to the apex
Flashcard 21: Volume of a Sphere
Front: V = \frac{4}{3}\pi r^3
Back:
Purpose: Calculates the volume of a sphere.
Variables:
V: Volume
\pi: pi
r: radius of the sphere
Flashcard 22: Surface Area of a Rectangular Prism
Front: SA = 2(lw + lh + wh)
Back:
Purpose: Calculates the total surface area of a rectangular prism (sum of the areas of all six faces).
Variables:
SA: Surface Area
l: length
w: width
h: height
Flashcard 23: Surface Area of a Cylinder
Front: SA = 2\pi r^2 + 2\pi rh
Back:
Purpose: Calculates the total surface area of a cylinder (area of two circular bases plus the area of the curved side).
Variables:
SA: Surface Area
\pi: pi
r: radius of the base
h: height of the cylinder
Flashcard 24: Surface Area of a Sphere
Front: SA = 4\pi r^2
Back:
Purpose: Calculates the total surface area of a sphere.
Variables:
SA: Surface Area
\pi: pi
r: radius of the sphere