Question

Use double-angle identity to find the exact value of each expression.
cos theta= (squareroot5/5)and 270 degrees 12 years ago

Answer 1

@ganeshie8

Answer 2

draw the angle first, and draw the reference triangle

Answer 3

??????

Answer 4

since we're given that 270 degrees<theta<360,
\(\theta \) lies somewhere in 4th quadrant as shown above^

Answer 5

can u find the other missing side in the triangle ?