Westonci.ca is the Q&A platform that connects you with experts who provide accurate and detailed answers. Get immediate and reliable solutions to your questions from a community of experienced professionals on our platform. Connect with a community of professionals ready to provide precise solutions to your questions quickly and accurately.

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

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

Sagot :

To find the value of [tex]\( x \)[/tex] for which [tex]\( \cos(x) = \sin(14^\circ) \)[/tex] in the interval [tex]\( 0^\circ < x < 90^\circ \)[/tex], we can use the co-function identity for trigonometric functions:

[tex]\[ \cos(x) = \sin(90^\circ - x) \][/tex]

Given the equation [tex]\( \cos(x) = \sin(14^\circ) \)[/tex], we can equate the expressions:

[tex]\[ \cos(x) = \sin(14^\circ) \][/tex]

By the co-function identity, we know:

[tex]\[ \cos(x) = \sin(90^\circ - x) \][/tex]

Therefore, we can write:

[tex]\[ \sin(90^\circ - x) = \sin(14^\circ) \][/tex]

Since the sine function is positive and strictly increasing in the range [tex]\( 0^\circ \)[/tex] to [tex]\( 90^\circ \)[/tex], the equality [tex]\( \sin(90^\circ - x) = \sin(14^\circ) \)[/tex] implies:

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

Solving for [tex]\( x \)[/tex], we get:

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

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

[tex]\[ x = 76^\circ \][/tex]

So, the value of [tex]\( x \)[/tex] is [tex]\( 76^\circ \)[/tex].

Therefore, the correct answer is:
[tex]\[ \boxed{76^\circ} \][/tex]
Thank you for your visit. We are dedicated to helping you find the information you need, whenever you need it. We hope our answers were useful. Return anytime for more information and answers to any other questions you have. Thank you for using Westonci.ca. Come back for more in-depth answers to all your queries.