Respuesta :

Given the expression:

sin(135° - 60°)

Let's find the exact value of the expression.

First simplify the expression in the parentheses:

sin(135° - 60°) = sin(75°)

The exact value of sin(75°) is:

[tex]sin(75^o)=\frac{\sqrt{2}+\sqrt{6}}{4}[/tex]

Part B.

Given the expression:

sin135° - cos60°

Let's find the exact value.

Apply the reference by finding the equivalent angle in the first quadrant.

[tex]\begin{gathered} 135-90=45^o \\ \\ \text{ Thus, we have:} \\ sin45-cos60 \end{gathered}[/tex]

We have the following:

[tex]\begin{gathered} Exact\text{ value of sin45=}\frac{\sqrt{2}}{2} \\ \\ Exact\text{ value of cos60=}\frac{1}{2} \end{gathered}[/tex]

Therefore, the exact value of the expression is:

[tex]\frac{\sqrt{2}}{2}=\frac{1}{2}[/tex]

ANSWER:

• Part A.

[tex]\begin{gathered} \frac{\sqrt{2}+\sqrt{6}}{4} \\ \end{gathered}[/tex]

• Part B.

[tex]\frac{\sqrt{2}}{2}-\frac{1}{2}[/tex]