Find the exact value of sin ( 2 a. if cos a = 3 /5 . assume a is a quadrant i angle in standard position.

asked Aug 10, 2019 71.8k views

2 votes

Find the exact value of sin ( 2

a. if cos a = 3 /5 . assume a is a quadrant i angle in standard position.

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4 votes

In a right angled triangle 'efg' cos a = 3/5
From Pythagoras theorem the third side will be 4
cos a =3/5
sin a =4/5
sin 2a =2 x 4/5
sin 2a= 8/5

Ashik Nesin answered Aug 15, 2019

7.7k points

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