" 21."(x+2)/(sqrt(x^(2)+2x+3))

(1)/(sqrt(21+4x-x^(2)))

lim_(x rarr2)(x^(3)-8)/(sqrt(x^(2)+x+2)-sqrt(3x+2))

lim_(x rarr oo)((sqrt(x^(2)+5)-sqrt(x^(2)-3))/(sqrt(x^(2)+3)-sqrt(x^(2)+1)))

If ( 3x- 4)/( sqrt(3x)+2) = 2+ ( sqrt(3x)- 2)/(2) , then find the value of x

((sqrt(x))^((3)/(5))times(sqrt(x))^((2)/(5))+2sqrt(x))/(2(sqrt(x))^((2)/(3))times(sqrt(x))^((1)/(3))+sqrt(x))=

int(dx)/(sqrt(21+4x-x^2))=

Find the roots of an equation by factorisation (2x-3)=sqrt(2x^(2)-2x+21)

Solve sqrt(x^(2)+4x-21)+sqrt(x^(2)-x-6)=sqrt(6x^(2)-5x-39)

Find the integral int(1)/(5-8x-x^(2))dx A. (1)/(2sqrt(21))log|(sqrt(21)+(x+4))/(sqrt(21)-(x+4))|+C .B. (1)/(2sqrt(21))log|(sqrt(21)-(x+4))/(sqrt(21)+(x+4))|+C C. (1)/(sqrt(21))log|((x+4)+sqrt(21))/((x+4)-sqrt(21))|+Cquad D. (1)/(sqrt(21))log|((x+4)-sqrt(21))/((x+4)+sqrt(21))|+C