help me with my homework?

Question

1.3 sin x- 2 sin x + sin x is equal to
a.o
b.2 sin x
c.-2 sin x
d.sin x

2.the sum of 5 cos x -tan x and 5 tan x - cos x is

a.6 cos x- 6 tan x
b.4 cos x - 4 tan x
c.cos x -13
d.4 cos x +13

3.when we subtract 2 cos x +5 from 3 cos x -8,the result is
a. cos x-3
b.-cos x -3
c.cosx -13
d.5 cos x + 13

4.when simplified,the expression
3 sin x + 5 sin x (cos x-sin x) is equal to
a.3 sin x + 5sin x cos x - 5 sin ^2 x
b.8 sin x cos x-8 sin^2 x
c.3 sin x + 5 sin x cos x - sin x
d.8 sin x - cos xsin x

5.the expression of sin^@ x-1 divided by sin x + 1 is equal to

a. sin x
b.sin x-1
c.1
d.sin x +1


you have to show youre solution

honestly speaking its really hard and i really need help and if you answered that i highly appreciated

Answer 1

1. 3sinx-2sinx+sinx = sinx(3-2+1)
= sinx (4-2) = sinx (2) = 2sinx = option b

2. (5 cosx - tanx)+(5tanx-cosx)
= 5cosx - cosx + 5tanx - tanx
= 4cosx + 4tanx = none of the given options

3. (3cosx - 8)-(2cosx + 5)
= 3cosx - 8 - 2cosx - 5
= 3cosx - 2cosx - 8 - 5
=cosx - 13 = option c

4. 3sinx+5sinx(cosx-sinx)
= 3sinx+5sinxcosx-5sin^2(x)=option a

5. (sin^2(x)-1)/(sinx+1)
use the identity a^2-b^2=(a+b)(a-b)
= [(sinx+1)(sinx-1)]/(sinx+1)
=sinx-1.............. [sinx+1 cancelled]
=option b

Answer 2

1) 3 sin x- 2 sin x + sin x is equal to
=(3-2+1)sinx
=2sinx
b. 2Sin x

2) the sum of 5 cos x -tan x and 5 tan x - cos x is
=(5-1)cosx +(5-1)tanx
=4cos x +4tanx
b. 4cos x +4tanx

3).when we subtract 2 cos x +5 from 3 cos x -8,the result is
=(3-2)cosx -8-5
=cosx -13
c. cosx -13

4)when simplified,the expression 3 sin x + 5 sin x (cos x-sin x) is equal to
(just multiply)
a.3 sin x + 5sin x cos x - 5 sin ^2 x

5)the expression of sin^2 x-1 divided by sin x + 1 is equal to
= (sinx +1)(sinx -1)/(sinx +1)
=sinx -1
b.sin x-1

Answer 3

The first three are the same ...

3 sin x- 2 sin x + sin x
= (3 -2 +1) sin x
= 2 sin x

So get all values of the same variable all together and solve them, and all constants together to solve them and you will have your answer.

You have to know algebra to solve these... good luck!

Answer 4

Sorry, I'd love to help but I can't. Why don't you ask a responsible adult who may know the answer? If I'd give you an answer, I'd be wrong.

Answer 5

IF you don't get it try asking your teacher for help. Not a bunch of people who may give you wrong answers. Now go do your own homework.