A mathematical sequence whose verb is equal is called

Given cos theta = - 2/5 and sin theta < 0, find the six trigonometric values. I need help with this

Lena [83]

Answer:

$\sin\,\theta =-\frac{\sqrt{21} }{5}$

$\tan\,\theta =\frac{\sqrt{21} }{2}$

$\sec\,\theta = \frac{-5}{2}$

$cosec\,\theta =\frac{-5}{\sqrt{21} }$

$\cot\,\theta =\frac{2}{\sqrt{21} }$

Step-by-step explanation:

$\cos\theta =\frac{-2}{5}$

As both $sin\,\theta$ ,

$\theta$ lies in the third quadrant.

In the third quadrant,

$\sin\theta$

$\sin\,\theta =-\sqrt{1-\cos^2\,\theta} \\=-\sqrt{1-(\frac{-2}{5})^2 } \\\\=-\sqrt{1-\frac{4}{25} }\\\\=-\sqrt{\frac{25-4}{25} }\\\\=-\frac{\sqrt{21} }{5}$

$\tan\,\theta = \frac{\sin\,\theta}{\cos\,\theta }\\\\=\frac{\frac{-\sqrt{21} }{5} }{\frac{-2}{5} }\\\\=\frac{\sqrt{21} }{2}$

$\sec\,\theta =\frac{1}{\cos\,\theta }\\\\=\frac{1}{\frac{-2}{5} }\\\\=\frac{-5}{2}$

$\ cosec \,\theta = \frac{1}{sin\,\theta }\\\\=\frac{1}{\frac{-\sqrt{21} }{5} }\\\\=\frac{-5}{\sqrt{21} }$

$\cot\,\theta =\frac{1}{\tan\,\theta}\\\\=\frac{1}{\frac{\sqrt{21} }{2} }\\\\=\frac{2}{\sqrt{21} }$

3 0

3 years ago

100 POINTS! NEED HELP QUICKLY! Look at picture below

Delvig [45]

Answer:

60, 75

150 165

240 255

330 345

Step-by-step explanation:

csc 4 theta = -2 sqrt(3)/3

Write in terms of sin

1/ sin (4 theta) = -2 sqrt(3)/3

Using cross products

-2 sqrt(3) = 3 sin (4 theta)

Divide each side by 3

-2 sqrt(3)/3 = sin (4 theta)

Take the inverse sin on each side

sin ^ -1(-2 sqrt(3)/3) = sin ^ -1 (sin (4 theta))

240 +360n = 4 theta

and 300 +360n = 4 theta where n is an integer

Dividing each side by 4

240/4 +360n/4 = 4/4 theta and 300/4 +360n/4 = 4/4 theta

60 + 90n = theta and 75 +90n = theta

We want all the values between 0 and 360

Let n=0

60, 75

n=1

60+90=150 and 75+90 =165

n=2

60+180= 240 75+180=255

n=3

60+270 = 330 75+ 270 =345

7 0

3 years ago

Which of these problem types can not be solved using the Law of Sines?

andrezito [222]

I think the answer is B!

Hope this helps

6 0

3 years ago

The square of a number plus three times the number is 70. find the numbers.

Harrizon [31]

Answer:

Step-by-step explanation:

The equation for that is

$x^2+3x=70$

If we subtract over the 70, we have a quadratic that we can factor to solve for the values of x that will make that equation true.

$x^2+3x-70=0$

Now we need the factors of 70 that will either add or subtract to give us the linear term of 3. The factors of 70 that will work are 10 and 7. 10 times 7 is 70, and 10 - 7 = 3:

$x^2+10x-7x-70=0$ and now we will factor by grouping: