Question

Lesson name:- Trigonometry

Evaluate the following:
1) cos² 45° + tan² 45° - 3 sin² 90°​

Answer 1

(1/√2)2+(1)2-3*(1)2

1/2+1-3

1+2-6/2

3-6/2

-3/2

Answer 2

➼ Answer ➼

$cos^{2}45$° $+tan^{2}45$° $-3sin^{2}90$°

$=>(\frac{1}{\sqrt{2}}^{2})+1^{2}-3*1^{2}$

$=>\frac{1}{2} +1-3*1$

$=>\frac{1}{2} +1-3$

$=>\frac{1}{2} +\frac{2}{2} -\frac{6}{2}$

$=>\frac{3}{2} -\frac{6}{2}$

$=>\frac{-3}{2}$

Hence,

The value is $\frac{-3}{2}$.

☆ Hope it Helps ☆