Prove: (1-cos(2A))/sin(2A) = tan(A)

Firstly we must lay out our double angle formulas which are required for this question: cos(2A) = 1-2sin^2(A) = 2cos^2(A)-1 sin(2A) = 2sin(A)cos(A) Working from LHS: (1-cos(2A))/sin(2A) Focusing on the denominator 1-cos(2A) = 1-(1-2sin^2(A)) = 2sin^2(A) Focusing on the numerator sin(2A) = 2sin(A)cos(A) Therefore, overall: (1-cos(2A))/sin(2A) = 2sin^2(A)/2sin(A)cos(A) = 2*sin(A)sin(A) / 2sin(A)*cos(A) = sin(A)/cos(A) = tan(A) AS REQUIRED 

RP

Related Maths A Level answers

All answers ▸

f(x)=x^3 + x^2 -10x +8 show that (x-1) is a factor of f(x), Factorise f(x) fully , sketch the graph of f(x)


Express cos(2x) in terms of acos^2(x) + b


Find the coordinates of the sationary points on the curve x^2 -xy+y^2=12


Find INT{2,1}{x^4 + 3x^2 + 2}