Find the best solutions to your problems with the help of IDNLearn.com's experts. Our experts provide timely and precise responses to help you understand and solve any issue you face.

For what value of [tex]$x$[/tex] is [tex]$\cos(x) = \sin(14^{\circ})$[/tex], where [tex][tex]$0^{\circ} \ \textless \ x \ \textless \ 90^{\circ}$[/tex][/tex]?

A. [tex]$31^{\circ}$[/tex]
B. [tex]$28^{\circ}$[/tex]
C. [tex][tex]$14^{\circ}$[/tex][/tex]
D. [tex]$76^{\circ}$[/tex]


Sagot :

To determine the value of [tex]\( x \)[/tex] such that [tex]\( \cos(x) = \sin(14^\circ) \)[/tex] within the range [tex]\( 0^\circ < x < 90^\circ \)[/tex], we can use a well-known trigonometric identity.

The trigonometric identity we will use is:
[tex]\[ \cos(x) = \sin(90^\circ - x) \][/tex]

We are given:
[tex]\[ \cos(x) = \sin(14^\circ) \][/tex]

By the trigonometric identity, we can express:
[tex]\[ \sin(14^\circ) = \cos(x) = \sin(90^\circ - x) \][/tex]

To find [tex]\( x \)[/tex], we then need to solve for [tex]\( x \)[/tex] in the equation:
[tex]\[ 14^\circ = 90^\circ - x \][/tex]

Let's solve for [tex]\( x \)[/tex]:

[tex]\[ 14^\circ + x = 90^\circ \][/tex]
[tex]\[ x = 90^\circ - 14^\circ \][/tex]
[tex]\[ x = 76^\circ \][/tex]

Thus, the value of [tex]\( x \)[/tex] that satisfies [tex]\( \cos(x) = \sin(14^\circ) \)[/tex] is:
[tex]\[ x = 76^\circ \][/tex]

Therefore, the correct answer is:
[tex]\[ \boxed{76^\circ} \][/tex]