Jan 17, 2015 · It's the same as $ [\cos (x)]^2$, which is really how this should be written. But it's kept around for historical reasons. Truthfully, the notation $\cos^2 (x)$ should actually mean $\cos (\cos …

Jun 27, 2019 · For 2D case I mean $\cos^2 \alpha + \cos^2 \beta =1$. In 3D case I can't see the relation between angles while in 2D case obviuosly $\alpha + \beta=\pi/2$

Oct 6, 2014 · How do you prove the following: Pythagorean trigonometric identity. For all $\theta\in [0,2\pi]$ it holds that $$ \sin^2\theta+\cos^2\theta=1.$$ I'm curious to know of the different ways of …

Jul 29, 2020 · $$\\cos^2(\\theta) + \\sin^2(\\theta) = 1$$ I solved this by using right triangle, $$\\sin(\\theta) = \\frac{a}{c}, \\quad \\cos(\\theta) = \\frac{b}{c}$$ $$\\cos^2 ...

Feb 24, 2016 · $\cos^2\theta$ is the same thing as $ (\cos\theta)^2$, it's just another notation. But these are different from $\cos (\theta^2)$.

Jan 28, 2020 · I have to find the general solution of this trigonometric equation $$\cos4 \theta = \cos2 \theta $$ I solved in the following manner, but I got the wrong answer.

$\cos^2 (\theta) + \sin^2 (\theta)$ is always equal to $1$ in the mathematical world. This is the Pythagorean Theorem. In the computer world, this is not so because computer arithmetic has limited …

Multiply $\mathrm e^ {\mathrm ix}=\cos (x)+\mathrm i\sin (x)$ by the conjugate identity $\overline {\mathrm e^ {\mathrm ix}}=\cos (x)-\mathrm i\sin (x)$ and use that ...

Jan 23, 2025 · Problem: If $$\tan \theta \tan \phi = \sqrt {\frac {a-b} {a+b}},$$ prove that $$ (a - b\cos 2\theta) (a - b\cos 2\phi) = a^2 - b^2.$$ My Attempt: I started with the ...

I'm just not familiar with the notation (was daydreaming during my trig classes unfortunately). So cos^2 (i) is the same as [cos (i)]^2?