It is 1.
If sine theta is 0.28, then theta is 16.26 degrees. Cosine 2 theta, then, is 0.8432
It also equals 13 12.
Until an "equals" sign shows up somewhere in the expression, there's nothing to prove.
-1
Cosine squared theta = 1 + Sine squared theta
If r-squared = theta then r = ±sqrt(theta)
It is 1.
To determine what negative sine squared plus cosine squared is equal to, start with the primary trigonometric identity, which is based on the pythagorean theorem...sin2(theta) + cos2(theta) = 1... and then solve for the question...cos2(theta) = 1 - sin2(theta)2 cos2(theta) = 1 - sin2(theta) + cos2(theta)2 cos2(theta) - 1 = - sin2(theta) + cos2(theta)
If sine theta is 0.28, then theta is 16.26 degrees. Cosine 2 theta, then, is 0.8432
You can use the Pythagorean identity to solve this:(sin theta) squared + (cos theta) squared = 1.
It also equals 13 12.
cos2(theta) = 1 so cos(theta) = ±1 cos(theta) = -1 => theta = pi cos(theta) = 1 => theta = 0
Until an "equals" sign shows up somewhere in the expression, there's nothing to prove.
2 sin^2 theta = 1/4 sin^2 theta = 1/8 sin theta = sqrt(1/8) theta = arcsin(sqrt(1/8))
cos2(theta) = 1 cos2(theta) + sin2(theta) = 1 so sin2(theta) = 0 cos(2*theta) = cos2(theta) - sin2(theta) = 1 - 0 = 1
If X and Y are sides of a right triangle, R is the hypoteneuse, and theta is the angle at the X-R vertex, then sin(theta) is Y / R and cosine(theta) is X / R. It follows, then, that X is R cosine(theta) and Y is R sin(theta)