If ` (3 ^x)= 81` then find x.

Find f(x)=7^(3+3x)(x gt0) , then find f'(x) .

If x,y,z , t gt 0 and xyzt=81 then minimum value of x+2y+z+8t is

Find (dy)/(dx) in the following : x^(3)+x^(2)y+xy^(2)+y^(3)= 81 .

If |x| is so small that x^4 and higher powers of x many be neglected , then find an approximate value of root(4)(x^2 + 81) - root(4)(x^2 + 16)

Find the derivative of f(x) = 3 at x = 0 and at x = 3.

Solve the equation 8x ^(3) - 36 x ^(2) - 18 x + 81 = 0 the roots being in A.P.

Prove that : If |x| is so small that x^(4) and higher powers of x may be neglected, then find the approximate value of root(4)(x^(2).+81)-root(4)(x^(2)+16).

If p(x) = x^(3) - 3x^(2) + 2x - 3 is a polynomial, then find the value of p(1).