Question 1162707
find the exact value of sin2x, and tan2x given cosx=2/3 and x is in quadrant 1
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Here's how I would do it:
Step 1, find the sin(x)
{{{sin(x) = sqrt(1 - cos^2(x))}}}
Step 2, find the sin(2x)
{{{sin(2x) = 2sin(x)cos(x)}}}
Step 3, find the cos(2x)
{{{cos(2x) = sqrt(1 - sin^2(x))}}}
Step 4, find the tan(2x)
tan = sin/cos
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If you don't know how to do that, it's time to learn how.