Question

Use the figure shown to determine which trigonometric ratio is incorrect?

a. sin 30°= 4/8
b. cos 60°=4/8
c. sin 60°= square root of 48 over 8
d. tan 30°= square root of 48 over 8

Answer 1

Option d is incorrect.

Explanation:

See the diagram attached.

a.
`\sin 30^(\circ) = (AB)/(AC) = (4)/(8)`. Hence, this is correct.

Here, sin Ф is given by perpendicular divided by the hypotenuse.

b.
`\cos 60^(\circ) = (AB)/(AC) = (4)/(8)`. Hence, this is also correct.

Here, cos Ф is given by base divided by the hypotenuse.

c.
`\sin 60^(\circ) = (BC)/(AC) = (√(48))/(8)`. Hence, this is also correct.

d.
`\tan 30^(\circ) = (AB)/(BC) = (4)/(√(48))`. Hence this is not correct.

Here, tan Ф is given by perpendicular divided by base.

Therefore, option d is incorrect. (Answer)