Find sin(2x), cos(2x), and tan(2x) from the given information. sin(x) = 3/5 , x in quadrant I
Solution:
Given, sin(x) = 3/5
We have to find the value of sin(2x), cos(2x), and tan(2x) in the first quadrant.
Let us use the know trigonometric identities to solve the given functions.
We know, sin2x + cos2x = 1
(3/5)2 + cos2x = 1
cos2x = 1 - (9/25)
cos2x = 16/25
Taking square root,
cos x = ±4/5
In the first quadrant cos x has to be positive.
Thus, cos x = +4/5
Now, sin 2x = 2 sinx cosx
sin 2x = 2(3/5)(4/5)
sin 2x = 24/25
We know, cos 2x = cos2x - sin2x
cos 2x = (4/5)2 - (3/5)2
cos 2x = (16/25) - (9/25)
cos 2x = (16 - 9)/25
cos 2x = 7/25
We know, tan 2x = sin 2x/cos 2x
tan 2x = (24/25)/(7/25)
tan 2x = 24/7
Therefore, the values of sin 2x, cos 2x and tan 2x are 24/25, 7/25 and 24/7.
Find sin(2x), cos(2x), and tan(2x) from the given information. sin(x) = 3/5 , x in quadrant I
Summary:
From the given information. sin(x) = 3/5 , x in quadrant I, the values of sin 2x, cos 2x and tan 2x are 24/25, 7/25 and 24/7.
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