How do you find sin^-1 (cos(pi/6))?

1 Answer
sankarankalyanam
Apr 18, 2018

color(blue)(sin^-1 (cos (pi/6)) = pi/3 " or " 60^@

Explanation:

![www.math-only-math.com/images/http://trigonometrical-ratios-table.png](https://useruploads.socratic.org/Rod2GhDAR8qhxzUwIaKk_trigonometry%20values.png)

"Let " theta = sin^-1 (cos (pi/6))

From the table above, cos (pi/6) = (sqrt3/2)

:. theta = sin^-1 (sqrt3/2)

sin theta = sqrt3/2

But sin 60 = sqrt3/2 as seen in the table.

Hence color(blue)(theta = sin ^-1 (sin (60)) = 60^@ " or " pi/3

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