Answer: 
<u>Step-by-step explanation:</u>
It is given that θ is between 270° and 360°, which means that θ is located in Quadrant IV ⇒ (x > 0, y < 0). Furthermore, the half-angle will be between 135° and 180°, which means the half-angle is in Quadrant II ⇒ 
It is given that sin θ = 
⇒ y = -7 & hyp = 25
Use Pythagorean Theorem to find "x":
x² + y² = hyp²
x² + (-7)² = 25²
x² + 49 = 625
x² = 576
x = 24
Use the "x" and "hyp" values to find cos θ:
Lastly, input cos θ into the half angle formula:
Reminder: We previously determined that the half-angle will be negative.
What’s angle 1? U need to post a pic
I'll solve 21, and you then should be able to solve the rest on your own!
Since ADC is 135, that means that that whole angle is 135 degrees. In addition, since angles ADB and BDC add up to ADC, we get ADB+BDC=ADC=135=11x+9+7x=18x+9. Subtracting 9 from both sides, we get 126=18x. Dividing both sides by 18, we get x=7. Plugging that into 11x+9=BDC, we get 11*7+9=77+9=86
Answer:
Step-by-step explanation:
x 0 , VCB ln(1 4x2 ) tương đương với
Answer:
f(2) = 0
Step-by-step explanation:
Evaluate the function at x = 2.
f(x) = -3x^2 + 6x
f(2) = -3(2^2) + 6 * 2
f(2) = -3(4) + 12
f(2) = 0
