If a curve y = a√x + bx passes through the point (1, 2) and the area bounded by the curve, line x = 4 and x-axis is 8 sq. units, then
(A) a = 3, b = -1
(B) a = 3, b = 1
(C) a = -3, b = 1
(D) a = -3, b = -1
Answer is (A) a = 3, b = -1
Given curve y = √ax + bx. This curve passes through (1, 2).
Therefore, 2 = a + b. (1)
Area bounded by this curve and line x = 4 and x-axis is 8 sq. units, then
From equations (1) and (2), we get a = 3, b = -1.
