Given:
must correctly answer 80% of the questions
correctly answered questions = 26
incorrectly answered questions = 4
unanswered questions = 15
Total questions = 26 + 4 + 15 = 45
45 * 80% = 36 required correctly answered questions.
36 - 26 = 10
Out of 15 remaining questions, 10 questions must be correctly answered for Heidi to advance to the next level.
The angle of STV would be 140 degrees.
Answer:
We have the function:
r = -3 + 4*cos(θ)
And we want to find the value of θ where we have the maximum value of r.
For this, we can see that the cosine function has a positive coeficient, so when the cosine function has a maximum, also does the value of r.
We know that the meaximum value of the cosine is 1, and it happens when:
θ = 2n*pi, for any integer value of n.
Then the answer is θ = 2n*pi, in this point we have:
r = -3 + 4*cos (2n*pi) = -3 + 4 = 1
The maximum value of r is 7
(while you may have a biger, in magnitude, value for r if you select the negative solutions for the cosine, you need to remember that the radius must be always a positive number)
