Rewrite 2cos x + 1 = 0 as:

2 cos x = -1, and then cos x = -1/2

x must be in Quadrant II or Quadrant III, since the adj. side is negative.

Note that the angle 120 has adj. side -1 and hyp 2. So 120 degrees is one solution.

Now what about a possible 2nd solution, to be found in Quadrant III? That would be -120 degrees, which has the same terminal line as does 240 degrees.

No soap.

So, the solution is 120 degrees.

6 0

2 years ago

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I need help with this problem?

Cerrena [4.2K]

Answer:

Step-by-step explanation:

Volume of cylinder:

$\boxed{\text{Volume of cylinder=$\pi r^{2}h$}}$

Bottom cylinder:

1 inch = 2.54 cm

diameter = 14 in

r = 14/2 = 7 in

r = 7 *2.54 = 17.78 cm

h = 4 in = 4*2.54 = 10.16 cm

Volume = 3* 17.78 * 17.78 * 10.16

= 9635.59 in³

Upper cylinder:

diameter = 12 in

r = 12/2 = 6in

r = 6*2.54 = 15.24 cm

h = 12 in = 12*2.54 = 30.48 cm

Volume = 3 * 15.24 *15.24 * 30.48

= 21237.63 in³

Volume of the object = 9635.59 + 21237.63

= 30873 cm³

3 0

2 years ago

I need help with 17, 19, 21, and 23.

Evgen [1.6K]

17. 2x<16 x=7 or lower
All I can help you with is #17,
sorry that I can't answer the other 3.
I hope this helped! :-)

7 0

2 years ago

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