Let f(x)=∫1x 2−t2dt. Then the real roots of the equation x2−f′(x)=0 are
± 1
± 1/2
0 and 1
Using Property 18, we have f′(x)=2−x2
and thus the given equation reduces to x2−2−x2=0
⇒x2+2x2−1=0. Thus the real roots are given by x = ± 1.