Final answer:
To evaluate csc 40°, we can find the reciprocal of sin 40° and round to the nearest tenth.
Step-by-step explanation:
To evaluate the expression csc 40° to the nearest tenth, we can use a calculator or reference table.
csc 40° is the reciprocal of sin 40°. Using a calculator, we find that sin 40° is approximately 0.6428.
Therefore, csc 40° is approximately 1/0.6428 which is approximately 1.555.
To the nearest tenth, csc 40° is approximately 1.6. Therefore, the correct answer is A. 1.6.