If f:[1,∞)→[2,∞) is given by f(x)=x+1x, then f−1(x) equals
x+x2−42
x1+x2
x−x2−42
1+x2−4
f:[1,∞)→[2,∞) f(x)=x+1x=y or x2−yx+1=0 or x=y±y2−42
But given f:[1,∞)→[2,∞)∴ x=y+y2−42 or f−1(x)=x+x2−42