Question

Sam used his calculator to find cos 1.75. he wrote down cos 1.75 = .999. how could sam recognize that his answer is incorrect?

Answer 1

Answer:

Step-by-step explanation:

Since π=3.14 and 1.75 should be half of π so cos(1.75) should be in the approximation of $\frac{\sqrt{2}}{2}$ or $0.7$.

Clearly Sam's calculator is in the degree mode since $cos(1.75^{\circ})$

is about $.999$ and obviously, $\frac{{\pi}}{2}$, So on the unit circle, it will be in the second quadrant.

Thus, cos(1.75) is negative.