precalc section 1.1-1.3

Pythagorean therom

a²+b²=c²

Distance Formula

d = √ (x₂ - x₁)² + (y₂ - y₁)²

midpoint formula

Midpoint = ((x1 + x2) / 2, (y1 + y2) / 2) 2 cords NOT multiply

x-intercept

Set Y=0 and solve for X

Y- intercept

set X=0 and solve for Y

y-axis symmetry

change x to -x, If the equation remains the same, it's symmetric over the y-axis.

x axis symmetry

Replace y with -y. If it stays the same, it's symmetric over the x-axis.

Origin symmetry

replace both x and y with -x and -y

slope intercept form

y=mx+b mx=slope, 3x=3/1 b= y intercept, 3= 0,3

when given 2 points and told to find the slope use…

slope formula

slope formula

m= y₂-y₁ / x₂-x₁

point slope form, insert given m z and y

y-y₁=m(x-x₁)

Find the equation of a line passing through two points

Use slope formula to find slope and then pick a point and use point slope form

Parallel

m₁=m₂ check with point slope form

Perpendicular

m₁x m₂= -1

example 5/3 and - 3/5