Question

If A lies in 2nd quadrant and 3tanA+4=0 then value of 2cotA-5cosA+sinA=?

Answer 1

As you know A lies in 2nd quadrant
tan x is -ve for x in 2nd quadrant,x > 90
$tan(A) = \frac{-4}{3}$
$cot (A) = \frac{1}{tan(A)} = \frac{-3}{4}$
$sin(A) = \frac{4}{5}$
$cos(A) = \frac{-3}{5}$

$2cot(A) - 5cos(A) + sin(A) = 2\frac{-3}{4}-5\frac{-3}{5}+ \frac{4}{5} = 2.30$