Answer:
Therefore, the polynomial function with exactly 8 roots is f(x) = (3x^2 - 4x - 5)(2x^6 - 5).
Step-by-step explanation:
brainliest plzz
First, recall that
cos(A - B) = cos(A) cos(B) + sin(A) sin(B)
so you just need to find cos(A) and sin(B).
Since both A and B end in the second quadrant, you know that
• cos(A) and cos(B) are both negative
• sin(A) and sin(B) are both positive
Then from the Pythagorean identity, you get
cos²(A) + sin²(A) = 1 ==> cos(A) = -√(1 - sin²(A)) = -2√10/7
cos²(B) + sin²(B) = 1 ==> sin(B) = +√(1 - cos²(B)) = √21/5
You'll end up with
cos(A - B) = (-2√10/7) (-2/5) + (3/7) (√21/5)
… = (4√10 + 3√21)/35
(which makes the last sentence in the question kind of confusing, because this expression doesn't get much simpler and it's certainly not a rational number)
Alright, lets get started.
tan Ф = -21
Using inverse function,
Ф =
Using calculator, we could find ta inverse value
Ф = - 87.3°
But as per given question, angle must lie between 0 and 180 degrees.
Means angle should present in first or second quadrant.
As tan value is given negative (-21), means angle will be in second quadrant.
If we add 180 degrees in our angle, the angle will lie in second quadrant. (refer the diagram)
Ф = - 87.27 + 180 = 92.73°
Ф = 92.73° : Answer
Hope it will help :)
Answer:
0
Step-by-step explanation:
By definition, if it is on the y-axis the x-coordinate is 0