If `(x^2)/4+(y^2)/9=1,` then find the range of `2x+ydot`

Find the range of 4^(x)+2^(x)-1

If x in[-9,3) then find the range of x^(2)

If (x^(2))/(144)-(y^(2))/(25)=1 . Find the range of (144)/(x)+(25)/(y) .

Find the range of: y=sqrt(1-x^(2))

Find the range of , f(x)=1/(4-x^2)

In A B C Prove that cos^2A/2+cos^2B/2+cos^2C/2lt=9/4dot In cos^2A/2+cos^2B/2+cos^2C/2=y(x^2+1/(x^2)) then find the maximum value of ydot

If (x+y): (x-y)= 4:1, then find the ratio (x^(2)+y^(2)):(x^(2)-y^(2))

If R={(x,y): x,y in W, x ^(2)+y^(2)=25} , then find the domain and range or R.

Q.If x be real,then find the range of the following rational expressions (i) (x^(2)+x+1)/(x^(2)+1) (i) y=(x^(2)-2x+9)/(x^(2)-2x-9)