It is given that, has its extreme values at x = 1 and x = 2.
at x = 1 and x = 2
Differentiating both sides with respect to x, we get
Subtracting (1) from (2), we get
6b = −1
Putting in (1), we get
Thus, the values of a and b are and , respectively.
Hence, the ordered pair (a, b) is .
If y = alogx + bx2 + x has its extreme values at x = 1 and x = 2, then (a, b) = .
RD Sharma XII Vol 1 (2019)