Respuesta :

Answer:

b. csc x

Step-by-step explanation:

cos x cotx + sin x

We know that cot = cos/sin

cos x cos x/ sin x + sin x

cos^x /sin x + sin x

Getting a common denominator of sin x

cos^2 x /sin x + sin x * sin x / sin x

cos ^2 x / sin x + sin^2 x / sin x

( cos ^2 x + sin^2 x) / sin x

We know that cos ^2 x + sin^2 x = 1

1 / sin x

We know that 1 / sin x = csc x

csc x

Answer:

b. csc x

Step-by-step explanation:

To simplify the expression;

cos x cotx + sinx  

But cot x = [tex]\frac{cos x}{sinx}[/tex]

Substitute cot x = [tex]\frac{cos x}{sinx}[/tex]  into the initial expression

cos x cotx + sinx

 

= [tex]cos x. \frac{cos x}{sinx} + sin x[/tex]  

= [tex]\frac{cos^{2} x}{sinx} + sin x[/tex]

= [tex]\frac{cos^{2} x + sin^{2}x }{sin x}[/tex]       But  [tex]sin^{2}x + cos^{2}x = 1[/tex]

=  [tex]\frac{1}{sinx}[/tex]                 But [tex]\frac{1}{sinx}[/tex]= cosec x

= cosec x

Therefore,  cos x cotx + sinx   =  cosec x