Trigonometry help:
$\cos \alpha$/$\cos \beta$=a,
$\sin \alpha$/$\sin \beta$=b then $\sin^2\beta$ is.
Note:
$\sin \beta$
=b/$\sin \alpha$
[Math] $\cos \alpha$/$\cos \beta$=a, $\sin \alpha$/$\sin \beta$=b then $\sin^2\beta$ is
trigonometry
trigonometry
Trigonometry help:
$\cos \alpha$/$\cos \beta$=a,
$\sin \alpha$/$\sin \beta$=b then $\sin^2\beta$ is.
Note:
$\sin \beta$
=b/$\sin \alpha$
Best Answer
We have $\cos\alpha=a\cos\beta$ and $\sin\alpha=b\sin\beta$. Square both sides of both equations and add. We get $$1=a^2\cos^2\beta+b^2\sin^2\beta.\tag{1}$$ Now use the fact that $\cos^2\beta=1-\sin^2\beta$. Substitute in Equation (1), and $\sin^2\beta$ is a small step away.