phinah 18 May 2018, 10:17
How is the sine of sixty degrees a negative number in radians?
4. Integration: Basic Trigonometric Forms
When I enter sin 60 into my calculator in degrees the result returned is .866.
When I enter sin 60 in radians the result is -.3048.
X
How is the sine of sixty degrees a negative number in radians?
Relevant page <a href="https://www.intmath.com/methods-integration/4-integration-trigonometric-forms.php">4. Integration: Basic Trigonometric Forms</a> What I've done so far When I enter sin 60 into my calculator in degrees the result returned is .866. When I enter sin 60 in radians the result is -.3048.
Murray 19 May 2018, 00:38
@Phinah
Using the conversion `pi` radians `= 180^@`, we have:
`1` radian `= (180^@)/pi`
`60` radians `= (60 xx 180^@)/pi`
Multiply this out and then convert it to an "ordinary" angle less than `360^"o"`
Can you see why `sin 60` radians is negative now?
X
@Phinah Using the conversion `pi` radians `= 180^@`, we have: `1` radian `= (180^@)/pi` `60` radians `= (60 xx 180^@)/pi` Multiply this out and then convert it to an "ordinary" angle less than `360^"o"` Can you see why `sin 60` radians is negative now?
phinah 26 May 2018, 13:47
NOW I CAN, thanks to you.
The answer is 3438`^@` rounded. Divided by 360`^@` shows that it is 9.55 complete revolutions which has a terminal side of around 198`^@`. Sine in the third quadrant is negative so this angle has a value of -.301.
Numbers have been rounded.
X
NOW I CAN, thanks to you. The answer is 3438`^@` rounded. Divided by 360`^@` shows that it is 9.55 complete revolutions which has a terminal side of around 198`^@`. Sine in the third quadrant is negative so this angle has a value of -.301. Numbers have been rounded.
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