99 Percentile Qs Bank for JEE MainMathematicsArea Under Curves
If a curve y= a x + b x passes through the point (1,2) and the area bounded by the curve, line x=4 and X -axis is 8 sq. units, then
Options
- Aa =3, ~b =-1
- Ba =3, ~b =1
- Ca =-3, ~b =1
- Da =-3, ~b =-1
Correct answer
A. a =3, ~b =-1
Step-by-step solution
The given curve passes through (1,2) . 2=a+b According to the given condition, ₀^4(a x +b x) d x=8 ...(i) 2 a 3 [x^ 3 / 2 ]₀^4+ b 2 [x^2 ]₀^4=8 2 a 3 8+8 ~b =8 2 a+3 b=3 ...(ii) From (i) and (ii), we get a =3, ~b =-1