Math Module 1 Question 19

In an isosceles triangle $ABC$, $cos(A)=\frac{12}{13}$ and $cos(B)=-0.70$. What is the value of $sin(C)$ in simplified fraction?
Answer:
Answer:
5/13

Explanation

The correct answer is $\frac{5}{13}$

Draw a diagram for the right-angled triangle as described in the question and then find $sin(C)$.

✨ Expert's Tip ✨

An angle is greater than $90°$ and less than $270°$ when the cosine of the angle is negative, based on unit circle trigonometry.

    About Exxcel

    Exxcel was established by a team of dedicated educators and experienced test writers who share a common goal: to equip students with the tools they need to excel in their exams. As an online Digital SAT® test preparation platform, our mission is to empower students to realize their full potential through mentorship and the delivery of high-quality, accessible education.

    College Board® is a trademark registered by the College Board, which is not affiliated with, and does not endorse, this website. Exxcel is unaffiliated with College Board® and do not have access to College Board's proprietary data.