1.

The intercepts on x-axis made by tangents to thecurve, `y=int_0^x|t|dt , x in R ,`which are parallel to the line `y""=""2x`, are equalto(1) `+-2`(2) `+-3`(3) `+-4`(4) `+-1`A. `+-1`B. `+-2`C. `+-3`D. `+-4`

Answer» Correct Answer - A
`y=int_(0)^(x)|t|dt`
Case I: If `xgt0`
`y=int_(0)^(x)tdt=[(t^(2))/2]_(0)^(x)=(x^(2))/2implies(dy)/(dx)=x=2` (given)
`implies x=2` and `y=2`
`:.` eqution of tangent is `(y-2)=2(x-2)`
or `y-2x+2=0`
Hence `x` intercept `=`
Case II: `xlt0`
`-y=int_(0)^(pi)-tdt=[(-t^(2))/2]_(0)^(x)=(-x^(2))/2`
`:.(dy)/(dt)=-x=2`
`:. x=-2,:.y=-2`,
`:.` equation iof tangent is `y+2=2(x+2)`
or `2x-y+2=0`
`:.x` intencept `=-1`


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