cos theta - sin 20 = 0

Question

i need this for homework please

Answer 1

cos θ - sin 20° = 0

cos θ = sin 20°

θ = cos^-1(sin 20°)

 

Use your calculator to get the answer.

Answer 2

cosθ-sin20=0

cosθ=sin20

trig identity: cos([∏/2]-θ)=sinθ

cos(90-20)=sin20

cos70=sin20

θ=70º

note: sin20=0.342020 and cos70=0.342020