Q48 / 75 · JEE Main 2020 (05 Sep Shift 2) · Mathematics

If the lines x+y=a and x-y=b touch the curve y=x2-3x+2 at the points where the curve intersects the x-axis, then ab is equal to …

Correct answer: 0.5

Solution

y=x2-3x+2,  x+y=a,x-y=b

⇒x2-3x+2=0

x1=2  x2=1

Therefore, points are(2,0) (1,0)

b=2  a=1

∴ab=12=0.5

 

Hence, the correct answer is 0.5.

Relevant Questions