The Fresnel function S(x)=0xsin(12t2)dt was introduced in Section 4.3. Fresnel also used the function C(x)=0xcos(12t2)dt in his theory of the diffraction of light waves. a On what intervals is C is increasing? b On what intervals is C concave upward? c Use a graph to solve the following equation correct to two decimal places: 0xcos(12t2)dt=0.7 d Plot the graphs of C and S on the same screen. How are these graphs related?