Question

use the trigonometric function values of quadrantal angles to evaluate the expression below.
(\sin 270^{\circ})^2-(\cos 270^{\circ})^2

(\sin 270^{\circ})^2-(\cos 270^{\circ})^2 =
(simplify your answer, including any radicals. use integers or fractions for any numbers in the expression.)

Explanation:

Step1: Recall sine value of 270°

$\sin270^{\circ}=- 1$

Step2: Recall cosine value of 270°

$\cos270^{\circ}=0$

Step3: Substitute values into expression

$(\sin270^{\circ})^2-(\cos270^{\circ})^2=(-1)^2 - 0^2$

Step4: Calculate result

$(-1)^2 - 0^2=1-0 = 1$

Answer:

$1$