Given csc(A) = 60/16 and that angle A is in Quadrant I, find the exact value of sec A in simplest radical form using a rational denominator . Someone please help me!

Respuesta :

Answer:

[tex] \frac{15 \sqrt{209} }{209} [/tex]

Step-by-step explanation:

Objective: Understand and work with trig identies.

Recall multiple trig identies and manipulate them to get from cosecant to secant.

Given

[tex] \csc(a) = \frac{60}{16} [/tex]

Apply reciprocal identity csc a = 1/sin a.

[tex] \sin(a) = \frac{16}{60} [/tex]

Apply pythagorean identity to find cos a.

[tex]( \frac{16}{60}) {}^{2} + \cos(x) {}^{2} = 1[/tex]

[tex] \frac{256}{3600} + \cos(x) {}^{2} = 1[/tex]

[tex] \cos(x) {}^{2} = \frac{3600}{3600} - \frac{256}{3600} [/tex]

We can simplify both expression

[tex] \cos(x) {}^{2} = \frac{225}{225} - \frac{16}{225} [/tex]

[tex] \cos(x) = \frac{ \sqrt{209} }{15} [/tex]

Cosine is positve on quadrant 1 so that cos(a)

Apply reciprocal identity sec a= 1/ cos a.

The answer is

[tex] \sec(a) = \frac{15}{ \sqrt{209} } [/tex]

Rationalize the denominator.

[tex] \frac{15}{ \sqrt{209} } \times \frac{ \sqrt{209} }{ \sqrt{209} } = \frac{15 \sqrt{209} }{209} [/tex]