Alguien que me ayude ha resolver los ejercicios 3, 4 y 5 de verificacion de identidades trigonometricas ((urgente por favor necesito ayuda : ) ))?

3. )

<img src="https://tex.z-dn.net/?f=%7Bcos%5E4B-sen%5E4B%3D%7D%5C%5C%5C%5C%7Bcos%5E2B.cos%5E2B-sen%5E2B.sen%5E2B%3D%7D%5C%5C%5C%5C%7Bcos%5E2B%281-sen%5E2B%29-sen%5E2B%281-cos%5E2B%29%3D%7D%5C%5C%5C%5C%7Bcos%5E2B-cos%5E2B.sen%5E2B-sen%5E2B%2Bcos%5E2B.sen%5E2B%3D%7D%5C%5C%5C%5C%7Bcos%5E2B-sen%5E2B%3D%7D%5C%5C%5C%5C%7B1-sen%5E2B-sen%5E2B%3D%7D%5C%5C%5C%5C%7B1-2sen%5E2B" />

O también :

<img src="https://tex.z-dn.net/?f=%7Bcos%5E4B-sen%5E4B%3D%7D%5C%5C%5C%5C%7Bcos%5E2B.cos%5E2B-sen%5E4B%3D%7D%5C%5C%5C%5C%7B%281-sen%5E4B%29%281-sen%5E2B%29-sen%5E4B%3D%7D%5C%5C%5C%5C%7B1-2sen%5E2B%2Bsen%5E4B-sen%5E4B%3D%7D%5C%5C%5C%5C%7B1-2sen%5E2B%7D" />

5.

)

<img src="https://tex.z-dn.net/?f=%7B%20%5Csqrt%7B1%2Bctg%5E2x%7D%20.%20%5Csqrt%7Bsec%5E2x-1%7D.%20%20%5Csqrt%7B1-sen%5E2x%7D%20%20%3D%7D%5C%5C%5C%5C%7B%20%5Csqrt%7B1%2B%5Cfrac%7Bcos%5E2x%7D%7Bsen%5E2x%7D%7D%7D%20.%20%5Csqrt%7B%5Cfrac%7B1%7D%7Bcos%5E2x%7D-1%7D%20.%20%5Csqrt%7Bcos%5E2x%7D%20%3D%7D%5C%5C%5C%5C%7B%20%5Csqrt%7B%5Cfrac%7Bsen%5E2x%2Bcos%5E2x%7D%7Bsen%5E2x%7D%7D.%5Csqrt%7B%5Cfrac%7B1-cos%5E2x%7D%7Bcos%5E2x%7D%7D.%5Csqrt%7Bcos%5E2x%7D%3D%7D%5C%5C%5C%5C%7B%5Csqrt%7B%5Cfrac%7B1%7D%7Bsen%5E2x%7D%7D.%20%5Csqrt%7B%5Cfrac%7Bsen%5E2x%7D%7Bcos%5E2x%7D%7D.%20%5Csqrt%7Bcos%5E2x%7D%3D%7D%5C%5C%5C%5C%7B%5Ctext%7Bcomo%20es%20una%20multiplicacion%20de%20fracciones%20con%20raices%20se%20puede%20simplificar%20%7D%7D%5C%5C%5C%5C%7B%5Csqrt%7B%5Cfrac%7B1%7D%7B1%7D%7D%3D%7D%5C%5C%5C%5C%7B%5Csqrt%7B1%7D%3D%7D%5C%5C%5C%5C%7B1%7D%5C%5C%5C%5C%7B%5Ctext%7Bsalu2.%21%21%20%3A%29%7D" />.