7.2-7.3 Review

Front

If cosx = -4/5, find secx.

Back

secx = -5/4

Front

Use a double-angle or half-angle identity to find tan(θ/2) given sin θ = -3/5 and 3π/2 < θ < 2π.

Back

tan(θ/2) = -1/3

Front

Use the Half-angle formulas to find sin 22.5º.

Back

sin 22.5º = √(2 - √2)/2

Front

Use a double-angle or half-angle identity to find sin 2θ given cos θ = 4/5 and 270° < θ < 360°.

Back

sin 2θ = -24/25

Front

Definition of secant (sec):

Back

Secant is the reciprocal of cosine: sec(x) = 1/cos(x).

Front

Definition of tangent (tan):

Back

Tangent is the ratio of sine to cosine: tan(x) = sin(x)/cos(x).

Front

Definition of sine (sin):

Back

Sine is a trigonometric function defined as the ratio of the opposite side to the hypotenuse in a right triangle.

Front

Definition of cosine (cos):

Back

Cosine is a trigonometric function defined as the ratio of the adjacent side to the hypotenuse in a right triangle.

Front

What is the double-angle formula for sine?

Back

sin(2x) = 2sin(x)cos(x).

Front

What is the double-angle formula for cosine?

Back

cos(2x) = cos²(x) - sin²(x).