Find the exact value of cos(a + b), given sin a = 2/5 for a in Quadrant || and cos B = 1/3 for b in Quadrant IV.

Option (4)

Step-by-step explanation:

cos(a + b) = cos(a)cos(b) - sin(a)sin(b) [Identity]

Since, sin(a) = for a in quadrant II

Therefore, cos(a) =

cos(a) =

But cosine of a is negative quadrant II

Therefore, cos(a) = -

And cos(b) = for b in quadrant IV

Therefore, sin(b) =

                           =

                           =

But sine of an angle is negative in quadrant IV,

Therefore, sin(b) =

Now substituting these values in the identity,

cos(a + b) =

                =

                =

Therefore, Option (4) will be the answer.  

it has changed from the width and the height.

step-by-step explanation:

step-by-step explanation:

two pairs of adjacent sides are of equal length. this implies that one diagonal divides the kite into congruent triangles, and so the angles between the two pairs of equal sides are equal in measure. it also implies that the diagonals are perpendicular.