For each of the following, decide if the given series is a geometric series. A. 5+25x+125x2+625x3+3125x4+⋯ : Is this a geometric series? A. Yes B. No If this is a geometric series, enter the first term: na and the ratio between successive terms: na (Enter na for the first term and ratio if this is not a geometric series.) B. 5x7+5x8+5x9+5x10+⋯ : Is this a geometric series? A. Yes B. No If this is a geometric series, enter the first term: na and the ratio between successive terms: na (Enter na for the first term and ratio if this is not a geometric series.) C. 5+5x+5x2+5x4+5x8+⋯ : Is this a geometric series? A. Yes B. No If this is a geometric series, enter the first term: na and the ratio between successive terms: na (Enter na for the first term and ratio if this is not a geometric series.)

A. Yes.

B. Yes.

C. No.

Step-by-step explanation:

A. Yes. The sum of the series, is the sum of a geometric series.

The first term of the series = 5.

The common ration or the ratio between successive terms (r) = (Answer)

B. Yes. The sum of the series, is also the sum of a geometric series.

The first term of the series .

The common ration or the ratio between successive terms (r) = (Answer)

C. No. The sum of the series, is not the sum of a geometric series.

The first term of the series .

(Answer)

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.