Question

cos 2θ - cos^2 θ = 0

Answer 1

i cant understand your question

Answer 2

use a double or half angle formula to solve the equation in the interval [0, 2pi]

Answer 3

hwyne can you plz solve this

Answer 4

a hollow metal sphere has an internal radius of 20 cm and an external radius of 30cm. given that the density of the metal is 7.8g/cm3 , find the mass of the sphere, your answer in kg

Answer 5

\(\cos(2\theta)=\cos^2(x)-sin^2(x)\)
so you have
\(\cos^2(x)-\sin^2(x)-cos^2(x) = 0\\\implies -\sin^2(x) = 0\\\implies \sin(x) = 0\\\implies x=\pi*k \ \ \ \text{ where } \ \ \ k\in \mathbb{Z}\)