Question

Without using calculator find : cos(225) sin(315) + sin( –270) tan(405)

Answer 1

Answer:

1.5

Step-by-step explanation:

225° bisects Q III

315° bisects Q IV

-270° = 90°

405° = 45° bisects Q I

cos(225) sin(315) + sin( –270) tan(405) = ?

      (-½√2)(-½√2) + 1(1) = ?

                          0.5 + 1 = 1.5

Answer 2

Answer:

Step-by-step explanation:

cos(225)*sin(315) + sin(-270)*tan(405)

=cos(360-135)*sin(360-45) + (-sin(360-90)*tan(180*3-135)

=cos135*(-sin45) + (-(-sin90)*(-cot135)

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

=1/2+1

=1+2/3

=3/3

=1