answer for all questions

answer for all questions of 4) or 19. If tana n tan N. The ehnunant ofthc equations x a coe a y — b

(18) . We have, \sin θ + \sin^{2} θ = 1 \Rightarrow \sin θ = 1 - \sin^{2} θ \Rightarrow \sin θ = \cos^{2} θ \Rightarrow \cos^{2} θ = \sin θ . . . . . . (1) Now, \cos^{2} θ + \cos^{4} θ = \cos^{2} θ + {(\cos^{2} θ)}^{2} = \sin θ + {(\sin θ)}^{2} [Using (1)] = \sin θ + \sin^{2} θ = 1 [As, \sin θ + \sin^{2} θ = 1]

Kindly ask the remaining queries in different threads.