Maths

Front (Question / Concept),Back (Answer / Formula)

Percentage Increase / Decrease formula,OriginalChange​×100

Reverse Percentages: How to find the original value before a 10% increase,Divide the new value by 1.10 (or multiply by 110100​)

Simple Interest formula,"I=100P×R×T​ (where P = Principal, R = Rate, T = Time)"

Compound Interest formula (Total Amount),A=P(1+100R​)n (where n = number of years)

"Gradient (m) of a line between (x1​,y1​) and (x2​,y2​)",m=x2​−x1​y2​−y1​​

Midpoint of a line segment formula,"(2x1​+x2​​,2y1​+y2​​)"

Length of a line segment formula,(x2​−x1​)2+(y2​−y1​)2​

"Perpendicular lines: If Line 1 has gradient m, what is the gradient of a line perpendicular to it?",−m1​ (The negative reciprocal)

The Quadratic Formula for solving ax2+bx+c=0,x=2a−b±b2−4ac​​

"Functions: What does f−1(x) mean, and how do you find it?","It means the Inverse Function. To find it, set y=f(x), swap x and y, and rearrange to solve for y."

"Trigonometry: Sine, Cosine, and Tangent ratios (SOH CAH TOA)","sin(θ)=HypOpp​, cos(θ)=HypAdj​, tan(θ)=AdjOpp​"

The Sine Rule (for non-right-angled triangles),sin(A)a​=sin(B)b​=sin(C)c​

The Cosine Rule for finding a side length,a2=b2+c2−2bccos(A)

Area of a Triangle using sine,Area=21​absin(C)

Interior angles of a polygon: Formula for the sum of interior angles,(n−2)×180∘ (where n is the number of sides)