What is the general solution for -9cos^2(θ)-1=6cos(θ) ?

The general solution for -9cos^2(θ)-1=6cos(θ) is θ=1.91063…+2pin,θ=-1.91063…+2pin

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

Popular >

-9cos^2(θ)-1=6cos(θ)

- 9 cos^{2} (θ) - 1 = 6 cos (θ)

θ = 1.91063 \dots + 2 πn, θ = - 1.91063 \dots + 2 πn

Solution steps

- 9 cos^{2} (θ) - 1 = 6 cos (θ)

Solve by substitution

cos (θ) = - \frac{1}{3}

cos (θ) = - \frac{1}{3} : θ = arccos (- \frac{1}{3}) + 2 πn, θ = - arccos (- \frac{1}{3}) + 2 πn

Combine all the solutions

θ = arccos (- \frac{1}{3}) + 2 πn, θ = - arccos (- \frac{1}{3}) + 2 πn

Show solutions in decimal form

θ = 1.91063 \dots + 2 πn, θ = - 1.91063 \dots + 2 πn

2 cos^{2} (x) = 1 + cos (x)

cos (2 x) = - 1, 0 \leq x \leq 2 π

arccot (x) + arctan (3) = \frac{π}{2}

tan (x) = \frac{9}{7}

5 sin (4 x) = - 10 sin (2 x)

What is the general solution for -9cos^2(θ)-1=6cos(θ) ?
The general solution for -9cos^2(θ)-1=6cos(θ) is θ=1.91063…+2pin,θ=-1.91063…+2pin