Answer to Question #162435 in Algebra for Samir khan

Question

Determine the primary and reciprocal trig ratios for the following angles.

a) (7pi)/4  

b) (- 2pi)/3

Answer 1

Primary:

$sin(7\pi/4) = -(\sqrt2/2)$

$cos(7\pi/4) = \sqrt2/2$

$tan(7\pi/4) = -1$

$sin(-2\pi/3) = -(\sqrt3/2)$

$cos(-2\pi/3) = -(1/2)$

$tan(-2\pi/3) = \sqrt3$

Reciprocal:

$sec(7\pi/4) = \sqrt2$

$csc(7\pi/4) = -\sqrt2$

$cot(7\pi/4) = -1$

$sec(-2\pi/3) = -2$

$csc(-2\pi/3) = -(2/\sqrt3)$

$cot(-2\pi/3) = \sqrt3/3$