Answer: C) For every original price, there is exactly one sale price.
For any function, we always have any input go to exactly one output. The original price is the input while the output is the sale price. If we had an original price of say $100, and two sale prices of $90 and $80, then the question would be "which is the true sale price?" and it would be ambiguous. This is one example of how useful it is to have one output for any input. The input in question must be in the domain.
As the table shows, we do not have any repeated original prices leading to different sale prices.
Step-by-step explanation:
(cos 10° − sin 10°) / (cos 10° + sin 10°)
Rewrite 10° as 45° − 35°.
(cos(45° − 35°) − sin(45° − 35°)) / (cos(45° − 35°) + sin(45° − 35°))
Use angle difference formulas.
(cos 45° cos 35° + sin 45° sin 35° − sin 45° cos 35° + cos 45° sin 35°) / (cos 45° cos 35° + sin 45° sin 35° + sin 45° cos 35° − cos 45° sin 35°)
sin 45° = cos 45°, so dividing:
(cos 35° + sin 35° − cos 35° + sin 35°) / (cos 35° + sin 35° + cos 35° − sin 35°)
Combining like terms:
(2 sin 35°) / (2 cos 35°)
Dividing:
tan 35°
Recall that
and
for all
. So


For
, we expect both
and
(i.e. the sine and cosine of any angle that lies in the first quadrant must be positive). By definition of absolute value,
if
.
So we have

making H the answer.
C is always true, because the inequality reduces to x > y.
Answer:
Step-by-step explanation:
Close number to 641 is 640
Close number to 59 is 60
Estimate for 641/59 ⇒ 640/60