First subtract 2 revolutions from the - 840 :- (- (840-720) = -120
This gives sin -120 which is in the 3rd quadrant of the unit circle
sin -120 = - sin 60 = - sqrt3/2
F(x) = 9x²<span> - 5x + 2
</span>f(-2) = 9(-2)² - 5(-2) + 2
<span>f(-2) = 36 + 10 + 2
</span><span>f(-2) = 48</span>
Dear SailorMars, #4's question is very convoluted so I won't show you how to do it. Luckily, I do know how to do #5 and #6. With #5, multiply 8 5/6 by two to get 17 2/3, then do 50-17 2/3 to get 32 1/3 ft of tape. With #6, add 11 1/2 and 6 4/5 to get 18.3 gallons of gas, then do 18.3-3 3/10 to get 15 gallons of gas used.
Answer:
32 sq. ft.
Step-by-step explanation:
1/2 (8x8)=1/2(64)=32