Cobalt-56 has a decay constant of 8.77 × 10-3 (which is equivalent to a half life of 79 days). how many days will it take for a sample of cobalt-56 to decay to 62% of its original value?

As I read this one, is just a decay exponential equation... so

A = P(1 + r)ᵗ   where "t" is days passed. . hmm in this case is decay, so negative rate  A = P(1 - r)ᵗ, and the decimal amount would be 0.00877 for the rate

62% of P, the original value, is just 0.62P, now... if we hmm take P as just 1, it could be any amount, but 62% of 1,000,000 is just 62% of 1 times 1,000,000

so, for the sake of comparing it with a percentage, 1 will do

Can you provide the tape diagram?

Hello!

the correct option is:

b. a value of the variable that makes the polynomial equal to zero.

why?

the root or roots of a polynomial are the values of the variable that makes the polynomial equal to 0. we can find the roots of a polynomial making the expression equal to 0 and then, isolating the variable (it it has just one variable).

for example, given the following polynomial:

the root or zero of the polynomial, can be found by making the expression equal to 0, and then, isolating the variable, so, finding the root we have:

therefore, we have that the root of the polynomial is equal to 2.

we must remember that the number of roots that a polynomial can have, will depend on the degree of the polynomial, a first degree polynomial have will have one single root, a second degree polynomial (quadratic expression) may have two roots and so.

hence the correct option is:

b. a value of the variable that makes the polynomial equal to zero.

have a nice day!