Trigonometric functions which are related by having the same value at complementary angles are called cofunctions. Cofunctions of complementary angles are equal.
A. csc 20' = csc(90-70)=sec 70
B. cos 87' = cos (90-3)=sin 3'
C. csc 40' = csc(90-50) =sec50'
D. tan 15' = tan(90-75)= cot 75'
Among all the option c is not correct.
Option C is false.
Well the answer would be 120=120 and 68=68
Using the profit concept, it is found that she makes a profit of $4 selling a dozen cookies for six dollars.
<h3>What is a profit?</h3>
The profit is given by the <u>subtraction of the revenue by the total costs</u>.
In this problem:
- For the dozen cookies, she earned a revenue of 6 dollars.
- In all, the total cost of the 12 cookies was of 0.5 + 0.7 + 0.4 + 0.4 = 2 dollars.
6 - 2 = 4, hence she makes a profit of $4.
More can be learned about the profit concept at brainly.com/question/4001746
The quotient of 78,600 and 12 is 6,550
