Question

If 3 cos A = 4 sin A , find the value of i) cos A ii) 3 − cot2A + cosec2A

Answer 1

ANSWER

3cosA=4sinA

tanA=43

tanA=BP=43

Using Pythagoras Theorem,

H2=P2+B2

H2=32+42

H2=52

H=5

Now, 3−cot2A+csc2A = 3−(PB)2+(PH)2

= 3−(34)2+(35)2

= 3−916+925

= 927−16+25

= 936

= 4