Answer:
Final answer is [tex]\cos\left(B\right)=\frac{15}{\sqrt{346}}[/tex] which is the last choice.
Step-by-step explanation:
In triangle ABC, we have been given a = 15, b = 11, and angle C is a right angle.
Now using those values, we need to find the exact value of cos B.
Apply Pythagorean formula:
[tex]AB^2=AC^2+BC^2[/tex]
[tex]AB^2=11^2+15^2[/tex]
[tex]AB^2=121+225[/tex]
[tex]AB^2=346[/tex]
[tex]AB=\sqrt{346}[/tex]
Now apply formula of cos
[tex]\cos\left(B\right)=\frac{BC}{AB}[/tex]
[tex]\cos\left(B\right)=\frac{15}{\sqrt{346}}[/tex]
Hence final answer is [tex]\cos\left(B\right)=\frac{15}{\sqrt{346}}[/tex]
