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How do I deal with parametric equations? x = 4 cos ( t + pi/6), y = 2 sin t, Show that x + y = 2sqrt(3) cos t.

Note: I have a screenshot of the question that I should be able to add to the work space. Q5 C4 June 2014 Edexcel.x + y = 2sqrt(3) cos tStart with x = 4 cos ( t + pi/6) and the trig identity cos(A + B) = cos...
KD
Answered by Karina D. • Maths tutor
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How do I know when to use the preterite or imperfect past tense?

The preterite tense indicates a single, completed action in the past. The imperfect indicates a continuous action in the past, a repeated action or a description. Let's take the verb 'comer', to eat, and the...
JB
Answered by JAGGER B. • Spanish tutor
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Prove that (1-cos2x)/sin(2x) = tan(x) where x ≠ nπ/2

Starting from the left hand side we can substitute the sin and cos sum and difference formulas. These are sin(A+B) = sinAcosB + cosAsinBand cos(A+B) = cosAcosB - sinAsinBBecause x = A = B when substituted th...
JB
Answered by Jed B. • Maths tutor
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How could you obtain a carboxylic acid from oxidation of an alcohol and what type of alcohol would be suitable?

Primary alcohol is the only alcohol which can fully oxidise as it first oxidises to an aldehyde and this can be further oxidised to a carboxylic acid. This is not possible with 2 0 alcohols as they oxidise t...
SH
Answered by Samuel H. • Chemistry tutor
2406 Views

solve the inequality x^2+4x-21>0

First we should try and factorise the polynomial the brackets will be (x+?) and (x-?) as the coefficient of x and the -21 have differing signs.just thinking of the factors of 21 we can see that 7-3 = 4 the f...
JL
Answered by Jake L. • Maths tutor
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