All categories

3 years ago

Solve: sin5x - cos2x + sin x = 0.

Mathematics

1 answer:

mote1985 [20]3 years ago

8 0

Answer:

x = 10 , 45 degrees.

Step-by-step explanation:

This seems a tricky one .

I guess we can use sin A + sin B = 2 sin (A+B)/2 cos (A - B) / 2

so sin 5x + sin x = 2 sin 3x cos 2x so our equation becomes

2 sin 3x cos 2x - cos 2x = 0

cos 2x ( 2 sin 3x - 1) = 0

so 2 sin 3x = 1

sin 3x = 1/2

giving 3x = 30 degrees and x = 10 degrees

or cos 2x = 0

so 2x = 90

giving x = 45 degrees.

You might be interested in

Find the volume of a cone with a diameter of 5.5 km

vagabundo [1.1K]

Answer:

$volume = \frac{1}{3} \pi {r}^{2} h \\ = \frac{1}{3} \times \frac{22}{7} \times {( \frac{5.5}{2}) }^{2} \times 11.2 \\ = 88.7 \: {km}^{3}$

4 0

2 years ago

Please help!! There’s 2 questions, Explain step by step pls :)

schepotkina [342]

Answer:

I'm late but the answer to the question on the left is 21 and the answer to the question on the right is 3.

Step-by-step explanation:

Remember that you have to complete the equations in order of PEMDAS.

19-3×4÷(-6)

For this equation, you would do 3×4 first (which equals 12) then divide that by -6 (Which equals - 2) and finally you would subtract that from 19. 19 - (-2)= 21

6(-8) / -12 - 1

For this equation you would do 6(-8) first (which equals -48) then divide that by -12 (which equals 4) and finally subtract 1 from that 4. 4-1=3

8 0

2 years ago

Solve this problem please!!

zavuch27 [327]

if I know how to do this I this it's y27 oh I know I wrong But it was worth a try right

Step-by-step explanation:

idffffk

7 0

2 years ago

Which of the following sets contain all roots of the polynomial

Zarrin [17]

All these given roots are contained in option C.

The given equation is :

$9x^{3}+9x^{2}-4x-4=0$

$9x^{2}(x+1)-4(x+1)=0$

$(9x^{2}-4)(x+1)=0$

$9x^{2}-4=0,x+1=0$

$x^{2}=\frac{4}{9},x=-1$

$x=\frac{2}{3},x=-1$

Roots = $-1,\frac{-2}{3} ,\frac{2}{3}$

Hence these lie in between $(\frac{-3}{2} ,\frac{3}{2})$

8 0

2 years ago

Find the smallest positive integer value of n for which 225n is a multiple of 540.

krek1111 [17]

Answer:

mark me as brainliest and follow and like my answer

Step-by-step explanation:

225n=540

n=2.4

5 0

2 years ago