\(\cfrac{sin50^\circ}{cos40^\circ}\) + \(\cfrac{cosec40^\circ}{sec50^\circ}\) - 4cos5° cos 40°
= \(\cfrac{cos(90^\circ-50^\circ)}{cos40^\circ}\) + \(\cfrac{sec(90^\circ-40^\circ)}{sec50^\circ}\) - 4 sin(90° - 50°) cosec40°
= \(\cfrac{cos40^\circ}{cos40^\circ}\) + \(\cfrac{sec50^\circ}{sec50^\circ}\) - 4 sin 40° x \(\cfrac{1}{sin40^\circ}\)
= 1 + 1 − 4
= −2
