The functions sin (), cos (), and tan () are part of the Standard C Library (as scanf () is).These functions are declared in the system header file math.h, which is automatically imported into your...

The functions sin (), cos (), and tan () are part of the Standard C Library (as scanf () is).These functions are declared in the system header file math.h, which is automatically imported into your program when you import Foundation.h. You can use these functions to calculate the sine, cosine, or tangent, respectively, of their double argument, which is expressed in radians.The result is also returned as a double precision floating-point value. So you can use this line to calculate the sine of d, with the angle d expressed in radians: result sin (d); Add a category called Trig to the Calculator class defined in Chapter 6,“Making Decisions.”Add methods to this category to calculate the sine, cosine, and tangent based on these declarations: -(double) sin; -(double) cos; -(double) tan;