Use the cofunction identities to evaluate the expression below without using calculator. sin²20° + sin²27° + sin²70° + sin²63° A)1 B) $\frac { 1 } { 2 }$ C)-1 D) 0 E)2

Question

Quizplus · Accepted Answer

Using the cofunction identity, sin(90° - θ) = cos(θ), we have sin²70° = cos²20° and sin²63° = cos²27°. Therefore, sin²20° + sin²70° = 1 and sin²27° + sin²63° = 1. Adding these results gives 1 + 1 = 2.

Use the Cofunction Identities to Evaluate the Expression Below Without 12\frac { 1 } { 2 }21​

Use the Cofunction Identities to Evaluate the Expression Below Without $\frac { 1 } { 2 }$