Write sin(x+1) in terms of unshifted sine and cosine. Write your answer using decimals. Please provide explanation, I’m confused.

sin(x + 1) = 0.841*cos(x) + 0.540*sin(x)

Step-by-step explanation:

Here we can use the relation:

Sin(a + b) = sin(a)*cos(b)  + sin(b)*cos(a)

In this case we have:

sin(x + 1)

This means that the graph of sin(x) is shifted one unit to the left.

But we can write this, using the above relation, as:

sin(x + 1) = sin(x)*cos(1) + sin(1)*cos(x)

Now we have no longer a shift, and we can replace:

sin(1) = 0.841

cos(1) = 0.540

Then:

sin(x + 1) = 0.841*cos(x) + 0.540*sin(x)

delaney would like to make a 5lb nut mixture that is 60% peanuts and 40% almonds.

she has several pounds of peanuts and several pounds of a mixture that is 20% peanuts and 80% almonds.

let 'p' represent the number of pounds of peanuts needed to make the new mixture, and  

let 'm' represent the number of pounds of the 80% almond-20% peanut mixture.

:

p + m = 5

therefore

m = (5-p)

write an equation based on the percent of peanuts

1p + .2m = .6(5)

replace m with (5-p)

p + .2(5-p) = .6(5)

p + 1 - .2p = 3

p - .2p = 3 - 1

.8p = 2

p = 2/.8

p = 2.5 lbs of peanuts required

then

5 - 2.5 = 2.5 lbs of the peanut/almond mixture required

:

a) what is the system that models this situation?

p + m = 5

1p + .2m = .6(5)