The richter scale is used to compare the intensities of earthquakes. an increase in 1 of magnitude on the richter scale represents a tenfold increase in intensity. an earthquake registers 7.4 on the richter scale and is followed by an aftershock that is 1000 times less intense. what is the magnitude of the aftershock?

c

step-by-step explanation:

we are given polynomial 2x^2 +4x +7.

we need to determine the number of roots of the given polynomial using the fundamental theorem of algebra.

a) for the given polynomial 2x^2+4x+7, we have degree =2.

b) let us find the roots of the given polynomial.

2x^2+4x+7= 0

  b:   ∠x = 28.6°, ∠y = 31.2°, ∠z = 120.2°

step-by-step explanation:

this is one of those questions where "test taking skill" is all you need. the only answer that has angles that sum to 180° is the one shown above. the remaining choices do not describe the angles of a triangle.

if you want to do more work than simply adding the offered numbers, you can also check them against the law of sines. it should be true that

  x/sin(x) = y/sin(y) = z/sin(z)

and all of these ratios must be greater than 15, the longest side length.

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if you want to solve the triangle from scratch, i'd suggest solving for the largest angle using the law of cosines.

  z² = x² +y² -2xy·cos(z)

  z = arccos((x² +y² -z²)/(2xy)) = arccos(-75.11/149.4) = 120.182°

now you can find y from the law of sines

  y = arcsin(y/z·sin(z)) = 31.242°