Register

Verify this cofunction identity by using the difference identity for cosine. Show your work! cos⁡(π/2-θ)=sinθ

Verify this cofunction identity by using the difference identity for cosine. Show your work! cos⁡(π/2-θ)=sinθ
7.8k views
0 votes
Verify this cofunction identity by using the difference identity for cosine. Show your work! cos⁡(π/2-θ)=sinθ

User Lawrence Kesteloot
by
8.8k points

1 Answer

4 votes
cos(A-B) = cosAcosB + sinAsinB

cos(π/2 - θ) = cos(π/2)cosθ + sin(π/2)sinθ

π/2 = 90°
cos(π/2) = cos90° = 0. sin(π/2) = sin90° = 1

cos(π/2 - θ) = cos(π/2)cosθ + sin(π/2)sinθ

= 0*cosθ + 1*sinθ = sinθ

Therefore cos(π/2 - θ) = sinθ

QED
User Omarrrio
by
8.2k points
← Prev Question Next Question →

Related questions

User Wdonahoe
asked May 27, 2018 206k views
Write the cofunction of an angle given the cosine 34 = .829038
Wdonahoe asked May 27, 2018
by Wdonahoe
8.7k points
1 answer
2 votes
206k views
Ask a Question
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Other Questions

What is .725 as a fraction
How do you estimate of 4 5/8 X 1/3
A bathtub is being filled with water. After 3 minutes 4/5 of the tub is full. Assuming the rate is constant, how much longer will it take to fill the tub?
i have a field 60m long and 110 wide going to be paved i ordered 660000000cm cubed of cement  how thick must the cement be to cover field
Write words to match the expression. 24- ( 6+3)
Link Copied!