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junior college 2 | H2 Maths

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##### Cell Tyh

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Help with the approximation!!

Date Posted: 1 month ago
Views: 36

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##### Boy Mow Chau's answer
125 answers (Tutor Details)
1st
Date Posted: 1 month ago
Boy Mow Chau
1 month ago
compared with the calculator value, our estimated value for sqrt(4.5) by using the expansion, is accurate to 3 decimal places.

in other words, the error is just about 0.01% !!
Boy Mow Chau
1 month ago
correction …

for the range of x for which the expansion is valid,
x<-sqrt(2) will result in square root of negative number.

in the topic of complex numbers in H2 maths, you learn about square root of negative numbers. sometimes you do have questions that involves mixed topics.

for this case here, we take it that we cannot have square root of negative numbers, so we should reject x<-sqrt(2), and state that the expansion is valid only for x>+ sqrt(2).