Question

Tan² 60° + 4 Cos² 45° + 3 Sec² 30° + 5 Cos² 90° =

A) 7 

B) 8 

C) 9 

B) 10

Answer 1

Correct option is: C) 9

\(Tan^2 60° + 4 Cos^2 45° + 3 Sec^2 30° + 5 Cos^2 90°\)

= \((\sqrt)^2 + 4 (\frac 1{\sqrt2})^2 + 3(\frac 2{\sqrt3})^2 + 5 \times 0^2\) (\(\because\) tan \(60^\circ\) = \(\sqrt3\), cos \(45^\circ\) = \(\frac 1{\sqrt2}\), sec \(30^\circ\) = \(\frac 2{\sqrt3}\)& cos \(90^\circ\) = 0)

= 3 + 4 \(\times\) \(\frac 12\) + 3 \(\times\) \(\frac 43\) + 0

= 3 + 2 + 4 = 9

Answer 2

Correct option is: A) 9