Given f(x)=sec x and g(x)=arcsin x, what is f(g(x))?

Answer choices:

A. Sqrt 1-x^2 / 1-x^2

B. Sqrt x^2+1 / x^2+1

C. Sqrt 1-x^2

D. Sqrt x^2+1

Respuesta :

Answer:

Option 1 is correct.

Step-by-step explanation:

Given two functions  f(x)=sec x and g(x)=arcsin x

we have to find f(g(x)).

f(g(x))=sec(arcsinx)=sec A where A=arc(sinx)

As, A=arc(sinx)

⇒ [tex]x=sin A=\frac{P}{H}[/tex]

⇒ P=x and H=1 gives [tex]B=\sqrt{1-x^2}[/tex]

hence, [tex]sec A=\frac{H}{B}=\frac{1}{\sqrt{1-x^2}}[/tex]

hence, [tex]f(g(x))=\frac{1}{\sqrt{1-x^2}}[/tex]

Rationalizing, we get

[tex]f(g(x))=\frac{\sqrt{1-x^2}}{1-x^2}[/tex]

Option 1 is correct.