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If y=tanx , prove that y2=2y y1 ....

If `y=tanx` , prove that `y_2=2y y_1` .

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Verified by Experts

We have given that
`y=tanx`
Therefore, `(dy)/(dx)=y_1=sec^2x`
`d/(dx)(y_1)=y_2=2secxd/(dx)(secx)`
`y_2=2sec^2xtanx`
`y_2=2yy_1`
Hence Proved
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