Cos2a. cos3a-cos2a. cos7a/sin4a. sin3a-sin2a. sin5a

Answer is -28.37

Step-by-step explanation:

from the numerator cos 2a×cos 3a - cos 2a×cos7a= cos6a^2 -cos 14a^2

= -cos8a^2 for the numerator

from the denominator;

sin4a×sin3a-sin2a×sin5a= sin12a^2 -sin10a^2

= sin2a^2

therefore, combining the equation it gives; -cos8a^2/sin2a^2

a^2 will divide each other,

= -cos8/sin2.

from the calculator,

= - 0.9903/0.0349

= -28.37

7

step-by-step explanation: