Question

find the value of cos 495 degree

Answer 1

cos 495=cos 135 = cos (180-45) = -cos 45 = 1/root2

Answer 2

Answer:

The value of cos 495 degrees is $\frac{\sqrt{2} }{2}$ or -0.70710678.

Step-by-step explanation:

Remove full rotations of $360^{\circ}$ until the angle is between $0^{\circ}$ and $360^{\circ}$.

$\cos (135)$

Apply the reference angle by finding the angle with equivalent trig values in the first quadrant.

Make the expression negative because cosine is negative in the second quadrant.

$-\cos (45)$

The exact value of $\cos (45)$ is $\frac{\sqrt{2}}{2}$

Or in Decimal Form:

-0.70710678..