Evaluate.
-$$\sin ^ { 2 } 45 ^ { \circ } + \cos ^ { 2 } 45 ^ { \circ }$$
A) $\frac { 1 } { 4 }$
B) 2
C) 0
D) 1

Question

Quizplus · Accepted Answer

This expression is an example of the Pythagorean identity in trigonometry, which states that $\sin^2\theta + \cos^2\theta = 1$ for any angle $\theta$. Therefore, regardless of the angle, in this case $45^\circ$, the sum of the square of the sine of the angle and the square of the cosine of the angle equals 1.

Evaluate - sin⁡245∘+cos⁡245∘\sin ^ { 2 } 45 ^ { \circ } + \cos ^ { 2 } 45 ^ { \circ }sin245∘+cos245∘

Evaluate
- $\sin ^ { 2 } 45 ^ { \circ } + \cos ^ { 2 } 45 ^ { \circ }$