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root3 (root6 + root12) can be written as Aroot2 + B

root3 (root6 + root12) (root3 * root6 ) + (root3 +root12) = root18 + root36= (root9 + root2) + 6= 3root2 +6a= 3 b = 6

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Write down the expansion of (cosx + isinx)^3. Hence, by using De Moivre's theorem, find cos3x in terms of powers of cosx.

First, we expand by using binomial expansion (it is always helpful to draw Pascal's triangle to find each term's coefficients): 1 1
1 2 1
1 3 3 1
Since the function is raised to the...

Answered by Hiro F. • Maths tutor

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v^2 = u^2 + 2as u = 12 a = –3 s = 18 (a) Work out a value of v. (b) Make s the subject of v^2 = u^2 + 2as

v^2 = 12^2+2(-3)(18) = 36. Therefore by square rooting v = 6.To make s the subject first minus u^2 from both sides to have v^2 -u^2 = 2as then divide 2a from both sides to have (v^2-u^2)/2a = s

Answered by Hershey Nicolle P. • Maths tutor

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A bottle contains 300ml of medicine, the dose for a child can be given by (m*a)/150 where m is the child's age in months and a is the adult dosage of 40ml. If you need 2 doses a day, how long will the medicine last until it's empty for a 2y/o child?

1) Work out the dosage required by the child per day 2 years old in months is 122 = 24. (12 is the number of months in a year and 2 is the child's age.)2440/150 = 6.4 ml (Using t...

Answered by Hershey Nicolle P. • Maths tutor

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