waec model questions vol1 2023 mathematics

Objective Question 2

Question 2 WAEC_MODEL_QUESTIONS_VOL1 • 2023
In a plane, vectors \(\mathbf{a}\) and \(\mathbf{b}\) have magnitudes \(|\mathbf{a}| = 5\) and \(|\mathbf{b}| = 8\). The resultant vector \(\mathbf{a}+\mathbf{b}\) makes an angle of \(30^{\circ}\) with \(\mathbf{a}\). Find the exact value of the dot product \(\mathbf{a}\cdot\mathbf{b}\).
Answer Options
A. 40/3
Correct Answer B. 80/3
C. 100/3
D. 80/5
Correct Answer
B

Master the Exam!

You've seen a preview, but there are thousands more questions plus AI tutor to break down complex solutions.

Unlock Full Access Available for Android & Windows
Chat with Support