Exponential Model

I’ve done the question in the additional assessment materials below.

For (A) I got 83
For (B) I got 10.7
For (C) I said you cannot take logs to negatives

I’m a bit unsure about C. Have I got the correct answer for B?

Reply 1

satsun

OP

17

From Edexcel AS Additional Assessment Materials.

Theta = 18 + 65e^-t/8

(edited 2 years ago)

Reply 2

mqb2766

21

Original post by satsun

I’ve done the question in the additional assessment materials below.

For (A) I got 83
For (B) I got 10.7
For (C) I said you cannot take logs to negatives

I’m a bit unsure about C. Have I got the correct answer for B?

I cant see the exponent in the image - too blurred.
A is right (units), B is probably about right, but would need to see the equation to check properly. C is sort of right, but it would be better to simply note that the exponential is always > 0, so the temperature is > 18 (the additive constant).

For B - just sub that time into the model and check you get the right temperature.

(edited 2 years ago)

Reply 3

satsun

OP

17

Original post by mqb2766

I cant see the exponent in the image - too blurred.
A is right (units), B is probably about right, but would need to see the equation to check properly. C is sort of right, but it would be better to simply note that the exponential is always > 0, so the temperature is > 18 (the additive constant).