cos3x-3cosx=cos2x+1 {Domain: 0<=x<=360} The solution is 90deg, 180deg, and 270deg, but what are the simplifying steps in between? I know all trig identities.

Step-by-step explanation:

cos(3x) − 3 cos x = cos(2x) + 1

Use triple and double angle formulas.

(4 cos³x − 3 cos x) − 3 cos x = (2 cos²x − 1) + 1

Simplify.

4 cos³x − 6 cos x = 2 cos²x

4 cos³x − 2 cos²x − 6 cos x = 0

2 cos³x − cos²x − 3 cos x = 0

Factor.

cos x (2 cos²x − cos x − 3) = 0

cos x (cos x + 1) (2 cos x − 3) = 0

Solve.

cos x = 0 → x = 90°, 270°

cos x + 1 = 0 → x = 180°

2 cos x − 3 = 0 → no solution

s + (a + 178) = 2000

step-by-step explanation:

2000 - 178 = 1822

1822 / 2 = 911

911 + 178 = 1089

1089 + 911 = 2000

abha = 1089

shane = 911

answer

d. 10

explanation

the distance from point y to wx is the height of the triangle.

using pythagoras theorem,

group similar terms to get,

this implies that,

take positive square root of both sides to get,

this implies that,