Question

sin 15° . cos 15°=?
plss answer my que I will mark u as brainlist and points...​

Answer 1

Answer:

sin15.cos15

sin15.cos(90-75)

sin15.sin75

sin(15+75)

sin90

1

Answer 2

$[(\sqrt{3} - 1) / 2\sqrt{2} ] * [(\sqrt{3} -+1) / 2\sqrt{2} ] = x$Solution:

Sin15 * Cos15 = X

Above equation can be written as

Sin(60–45) * Cos(60–45) = X

Apply Sin(A-B) and Cos(A-B)

(Sin60*Cos45 - Cos60*Sin45) * (Cos60*Cos45 + Sin60*Sin45) = X

$(\sqrt{3} /2 * 1/\sqrt{2} - 1/2 * 1/\sqrt{2} ) * ( 1/2 * 1/\sqrt{2} + \sqrt{3} /2 * 1/\sqrt{2}) = x$

$[( \sqrt{3} - 1)(\sqrt{3} + 1)]/4*2 = x$

After removing the breackets you would get $[\sqrt{9} + \sqrt{3} - \sqrt{3} - 1 ]/8$

Here,   => $\sqrt{9}$ = 3;

           => $\sqrt{3} and \sqrt{3}$ will get cancelled.

So the solution is 2/8

Please mark a brainliest..