An artifact originally had 16 grams of carbon-14 present. The decay model A = 16e-0.000121t describes the amount of carbon-14 present after t years. How many grams-14 will be present in 5715 years?

Which sum or difference identity would you use to verify that cos (180° - q) = -cos q? a.) sin (a -b) = sin a cos b – cos a sin b b.) cos (a -b) = cos a cos b – sin a sin b c.) cos (a -b) = cos a cosb + sin a sin b d.) sin (a + b) = sin a cos b + cos a sin b