سؤال 111

A sequence runs 5, 1, -3. Select all statements that are true about its common difference.

The common difference is -4.پاسخ درست
The common difference is 4, because a difference records how far apart two terms are.
Each term is found by adding -4 to the term before it.پاسخ درست
The common difference changes to -2 once the sequence passes zero.

توضیح

A common difference is found by taking a term away from the one that follows it, and one less five gives four below zero, the same value that three below zero less one gives. Reporting the plain gap of four throws away the direction, and the direction is the part that tells the sequence to fall rather than to rise.

توضیح

ادامهٔ این آزمون