We'll assume this is an arbitrary triangle ABC.
A) No, the sines of two different angles can be whatever they want
B) sin(B)=cos(90-B)
Yes, that's always true. The "co" in cosine means "complementary" as in the complementary angle, which adds to 90. So the sine of an angle is the cosine of the complementary angle.
C) No, the correct identity is sin(180-B)=sin B. Supplementary angles share the same sine.
D) Just like A, different triangle angles often have different cosines.
Answer: Choice B
Sqrt14 = 3.74 (2dp)
The principal root is always the positive.
Answer:
D
Step-by-step explanation:
The rest you can elimate because of obvious inferring and reasoning so process of elimination
Answer:

Step-by-step explanation:
Given
-- total
--- defective
--- selected
Required
The probability of rejecting the batch
This means that at least one of the selected piece is defected.
So, we first calculate the probability that all the selected piece are accepted.
So, we have:

The denominator decreases by 1 because it is a probability without replacement; 180 is subtracted from the numerator to represent the number of non-defective CDs
So, we have:


Using the complement rule, the probability that the batch will be rejected is:

