20) If the function f is continuous for all real numbers and lim as h approaches 0 of f(a+h) - f(a)/ h = 7 then which statement is true?
a) f(a) = 7
b) f is differentiable at x=a.
c) f is differentiable for all real numbers.
d) f is increasing for x>0.
e) f is increasing for all real differentiable
ans is B. Explain
21) d/dx(sin(cosx)) = ? Explain
22) Which of the following is true for y=x^4-2x^3? Ans is the curve has two points of inflection and one relative extremum. Explain
23) Integral of cos^2xsinxdx =? Explain
24) d/dx Integral with x on top and 1 on bottom of t^2dt=? Explain
25) Let r(t) be a differentiable function that is positive and increasing. The rate of increase of r^3 is equal to 12 times the rate of increase of r when r(t) = ?
Ans =2? Explain.
Because, function is continuous at all the points.
Lt(h->0) f(a+h)-f(a)/h = differentiation of f(x) at x = a which is acceptable, only when f(x) is continuous at x = a
Therefore, correct answer is B.
d/dx (sin(cosx)) = ...
There are a variety of calculus topics shown here, including differentiability, continuity, integration, and rate of change