Solution:
Given:
$7\cos^2\text{x}+3\sin^2\text{x}=4$
$\Rightarrow7\cos^2\text{x}+3\Big(1-\cos^2\text{x}\Big)=4$
$\Rightarrow7\cos^2\text{x}+3-3\cos^2\text{x}=4$
$\Rightarrow4\cos^2\text{x}+3=4$
$\Rightarrow4\Big(1-\cos^2\text{x}\Big)=3$
$\Rightarrow4\sin^2\text{x}=3$
$\Rightarrow\sin^2\text{x}=\frac{3}{4}$
$\Rightarrow\sin\text{x}=\frac{\sqrt{3}}{2}$
$\Rightarrow\sin\text{x}=\sin\frac{\pi}{3}$
$\Rightarrow\text{x}=\text{n}\pi\pm\frac{\pi}{3},\text{n}\in\text{Z}$
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Equation of horizontal line below x-axis at 5 units from x-axis is:
A single letter is selected at random from the word ‘PROBABILITY’. The probability that it is a vowel is:
$\frac{1}{3}$
$\frac{4}{11}$
$\frac{2}{11}$
$\frac{3}{11}$