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# C3 Numerical method question watch

1. f(x) e^x 3 sinx and the root is between (N, N+1) where lNl is less than or equal to 5. I have put the numbers 0 to 5 into the equation but they have all turned out positive, and I understand it that there is only a root if there is a change of sign. Help please!
2. (Original post by JustHoping)
f(x) e^x 3 sinx and the root is between (N, N+1) where lNl is less than or equal to 5. I have put the numbers 0 to 5 into the equation but they have all turned out positive, and I understand it that there is only a root if there is a change of sign. Help please!
Can you post the whole question exactly as you see it? A scan of the question would be good.
3. (Original post by JustHoping)
f(x) e^x 3 sinx and the root is between (N, N+1) where lNl is less than or equal to 5. I have put the numbers 0 to 5 into the equation but they have all turned out positive, and I understand it that there is only a root if there is a change of sign. Help please!
Not sure what your function is exactly without a screeenshot, but note that e^(anything) is always positive, so the only thing that can determine roots is the behaviour of the sine function. Are you sure you are in radians not degrees (or vice versa if the question specifies otherwise)?

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