a: \(y=4\cdot cosx-5\cdot sinx+2\)
=>\(y'=4\cdot\left(-sinx\right)-5\cdot\left(cosx\right)+0\)
=>\(y'=-4\cdot sinx-5\cdot cosx\)
c: \(y=sin3x+6\cdot cos4x-tan2x\)
=>\(y'=3\cdot cos3x+6\cdot4\cdot\left(-sin4x\right)-\dfrac{\left(2x\right)'}{cos^22x}\)
=>\(y'=3\cdot cos3x-24\cdot sin4x-\dfrac{2}{cos^22x}\)


















