8. Introduction to Trigonometry
medium

$8 \sin ^{2} 45-2 \tan ^{2} 60+3 \cot ^{2} 30-2 \cos ^{2} 45$

A

$5.5$

B

$6$

C

$4$

D

$5$

Solution

$8 \sin ^{2} 45-2 \tan ^{2} 60+3 \cot ^{2} 30-2 \cos ^{2} 45$

$=8\left(\frac{1}{\sqrt{2}}\right)^{2}-2(\sqrt{3})^{2}+3(\sqrt{3})^{2}-2\left(\frac{1}{\sqrt{2}}\right)^{2}$

$=8\left(\frac{1}{2}\right)-2(3)+3(3)-2\left(\frac{1}{2}\right)$

$=4-6+9-1=6$

Standard 10
Mathematics

Similar Questions

Start a Free Trial Now

Confusing about what to choose? Our team will schedule a demo shortly.