Consider the following function. 25 - dx x2 (a) Determine an appropriate trigonometric substitution. O Use x = tan(0), where - < 0 < since the integrand contains the expression V 25 – x². Use x = 25sec(0), where 0 s0 < or n < 0 < 2 since the integrand contains the expression V 25 – x 2 O Use x = 25sin(0), where since the integrand contains the expression 2 25 - x2. O Use x = 5sin(0), where - since the integrand contains the expression - x2. 2 25 - Зл since the integrand contains the expression 2 O Use x = 5sec(0), where 0 s0 < ~ or a s0 < 2 25 - O Use x = 5tan(0), where - < 0 < since the integrand contains the expression 2 - x2. 25 - (b) Apply the substitution to transform the integral into a trigonometric integral. Do not evaluate the integral. x4 dx = de 25 - x2