The amount of money in brian's savings account is given by the function m (t) = 50t 2 + 100t + 80, where t is the time in years. approximately how many years will it take brian to save $1,000?

His money in the savings account is given by m(t)=

The rate at which he is saving money can be obtained by differentiating the function.

m'(t)= 100t+100

So, in one year he saves

1001+100=200

In two years he saves

1002+100=300

In three years he saves

1003+100=400

Therefore, time taken to save 1000 dollars is

100t+100=1000

100t=900

t=9

Therefore, it will take 9 years to save $1000.

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