Question

What is the difference between $2\cos x$ and $\cos 2x$?

Answer 1

Difference between $2\cos x$ and $\cos 2x$.

• As the trigonometric function $2\cos x$ is twice the trigonometric function $\cos x$ whereas trigonometric function $\cos 2x$ is cosine of angle $2x$that is twice of angle $x$.
• The range of trigonometric function $2\cos x$ is between $-2$ and $2$ whereas range of trigonometric function $\cos 2x$ is between $-1$ and $1$.

Thus, the trigonometric function $2\cos x$ is twice the trigonometric function $\cos x$ whereas trigonometric function $\cos 2x$ is cosine of angle $2x$ that is twice of angle $x$.