\[ \int \frac {\cos \left (\frac {1}{2} b^2 \pi x^2\right )}{\text {FresnelC}(b x)} \, dx \]
Optimal antiderivative \[ \frac {\ln \left (\FresnelC \left (b x \right )\right )}{b} \]
command
integrate(cos(1/2*b^2*pi*x^2)/fresnel_cos(b*x),x, algorithm="fricas")
Fricas 1.3.8 (sbcl 2.2.11.debian) via sagemath 9.6 output
\[ \frac {\log \left (\operatorname {C}\left (b x\right )\right )}{b} \]
Fricas 1.3.7 via sagemath 9.3 output
\[ {\rm integral}\left (\frac {\cos \left (\frac {1}{2} \, \pi b^{2} x^{2}\right )}{{\rm fresnelc}\left (b x\right )}, x\right ) \]