Question

Value of expression (sin80 - cos 80) is postive or negative.Give reasons.

Answer 1

The value of (sin 80 - cos80) will be positive. The value of sin80 will be very close to that of sin90 (which is 1) and similarly, the value of cos80 will be very close to that of cos90 (which is zero). Clearly, the result will be positive decimal number and should be fairly close to 0.8.

Answer 2

Answer:

The value is positive.

Step-by-step explanation:

Given : Expression $\sin 80-\cos 80$

To find : The value of the expression ?

Solution :

Expression $\sin 80-\cos 80$

Calculate the value of each trigonometric term through calculator,

$\sin 80^\circ=0.98$

$\cos 80^\circ=0.17$

Substitute the value in the expression,

$\sin 80-\cos 80=0.98-0.17$

$\sin 80-\cos 80=0.81$

Therefore, The value is positive.