- Home
- Standard 10
- Mathematics
8. Introduction to Trigonometry
hard
જો $\sin A+\sin ^{2} A=1$ હોય, તો $\left(\cos ^{2} A+\cos ^{4} A\right)$ નું મૂલ્ય ............... છે.
A
$1$
B
$\frac{1}{2}$
C
$2$
D
$3$
Solution
Given, $\sin A+\sin ^{2} A=1$
$\Rightarrow$ $\sin A=1-\sin ^{2} A=\cos ^{2} A$ $\left[\because \sin ^{2} \theta+\cos ^{2} \theta=1\right]$
On squaring both sides, we get
$\sin ^{2} A=\cos ^{4} A$
$1-\cos ^{2} A=\cos ^{4} A$
$\cos ^{2} A+\cos ^{4} A=1$
Standard 10
Mathematics
