Answer:

Step-by-step explanation:
The method of variable substitution is a way of solving a system of equations. It involves solving one equation for a variable and then substituting in the expression that represents the value of the solved variable into the other equation. After doing so, one can solve for the unknown variable and then backsolve for the other variable.

In this system, the second equation is already solved for (y), thus one can substitute that expression into the other equation in the system.

Now solve using inverse operations,

Backsolve to find the value of (y), substitute in the value of (x), and solve for the value of (y).

Substitute,

Solve,

Thus, the answer to this system of equations is the following,
.
F(x) = x - 2sinx
To find for what values of x graph has tangents we need to differentiate function f(x).
f'(x) = 1-2cosx
Now, if we want to have horizontal tangents we need to make function f'(x) equal to 0 because at minimum or maximum of function f(x) tangent is horizontal.
1-2cosx = 0
cosx = 1/2
x = pi/3 + 2*n*pi and
x = -pi/3 + 2*n*pi
Explanation: cosx = 1/2 for both 60° and -60°. If we make one circle cosx will be equal to 1/2 for 420 and 300 degrees. Writing degrees in radians (using pi) we can write formulas above where 2*pi represents one full circle and n is an integer which represents how many circles we made.
Answer:
3 grams
Step-by-step explanation:
We are going to take the mass of a bunch of little strips below the triangle "roof." To do this, we must figure out what formula for the mass we'll use, in this case, we'll use:
Mass of strip = denisty * area = (1+x)*y*deltax grams
now, because the "roof" of the triangle contains two different integrals (it completely changes direction), we will use TWO integrals!
**pretend ∈ is the sum symbol
Mass of left part = lim x->0 ∈ (1+x)*y*deltax = inegral -1 to 0 of (1+x)*3*(x+1) = 3 * integral -1 to 0 of (x^2 + 2x + 1) = 3 * 1/3 = 1
Mass of left part = lim x->0 ∈ (1+x)*y*deltax = inegral 0 to 1 of (1+x)*3*(-x+1) = 3 * integral 0 to 1 of (-x^2 + 1) = 3 * 2/3 = 2
Total mass = mass left + mass right = 1 + 2 = 3 grams
Yes cause they are the same degree.