Application of DerivativeHard
Question
If 2a + 3b + 6c = 0, then at least one root of the equation ax2 + bx + c = 0 lies in the interval-
Options
A.(0, 1)
B.(1, 2)
C.(2, 3)
D.none
Solution
2a + 3b + 6c = 0
ax2 + bx + c = 0 has at least one roots
It proves Rolle′s theorem
∫f′(x)dx = ∫(ax2 + bx + c)dx
f(x) =
+ d
so f(x) =
+ d
for Rolle′s theorem
f(a) = f(b), (a, b) is interval given
So given (0, 1)
f(0) = d
f(1) =
+ d
f(1) = d
so f(0) = f(1) so the (0, 1) correct
ax2 + bx + c = 0 has at least one roots
It proves Rolle′s theorem
∫f′(x)dx = ∫(ax2 + bx + c)dx
f(x) =
so f(x) =
for Rolle′s theorem
f(a) = f(b), (a, b) is interval given
So given (0, 1)
f(0) = d
f(1) =
f(1) = d
so f(0) = f(1) so the (0, 1) correct
Create a free account to view solution
View Solution FreeMore Application of Derivative Questions
If a, b, c are positive numbers in G.P. and log , log and log are in A.P., then a, b, c forms the sides of a triangle wh...The slopes of the tangents to the curve y = (x + 1) (x − 3) at the points where it crosses x- axis are -...The area of triangle formed by tangent to the hyperbola 2xy = a2 and coordinates axes is-...The equation of the tangent to the curve 6y = 7 - x3 at point (1, 1) is -...The slope of the curve y = sin x + cos2 x is zero at the point, where-...