evaluating (1 Viewer)

[maths lover]

when a question in trigonometry is asking u to evaluate what is it exactly telling u to do.
for example evaluate sin(15)cos(15).

 

[Aindan]

use a formula. Hint, 2sinxcosx = sin 2x

 

[Trebla]

Evaluate = find the value

 

[gurmies]

It's asking you for a numerical expression. In this case, sin(15)cos(15) = 0.5*sin(30) = 0.25.

 

[Drongoski]

Find the value of.

e.g. 0.5 = sin 30 = sin (2 x 15) = 2 sin 15 cos 15 ==> sin15 cos 15 = 0.25

 

[Drongoski]

Hi gurmies - long time no see. Good to have you back.

 

[SpiralFlex]

Make sure you have exact value!

Long way:



Now using your compound formulae.



and



So now,







Now,





Times them: You will get

Short way:

 

[maths lover]

thanks guys

 

[gurmies]

Hi gurmies - long time no see. Good to have you back.

I'm humbled that somebody remembers!