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
