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That follows from the definition of the sine function. There are several equivalent definitions, but for example, it can be defined as the y-coordinate of the unit circle, as a function of the angle. You start measuring the circle from coordinates (1,0), and continue counterclockwise.

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This is because both sin definition is the length of line opposite to the angle divided by the angle side line. Since both lines are positive in the first quadrant, the sin value is positive.

Q: Why sin positive in 1st quadrant?

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1st quadrant is +x and +y.

There's a mnemonic for this: All Students Take Calculus. Starting in the first quadrant, and moving counterclockwise until the last, give each quadrant the first letter of thos words in order. A represents all 3, s represents sine, t represents tangent, and c represents cosine. If the letter appears in a quadrant, it is positive there. If not, it is negative there.In quadrant 2, only sine is positive.

The coordinates must be as follows: First quadrant: positive, positive Second quadrant: negative, positive Third quadrant: negative, negative Fourth quadrant: positive, negative

That's Quadrant - I .

Quadrant one is the upper right quadrant, or where both X and Y are positive.

Related questions

The value of tan and sin is positive so you must search quadrant that tan and sin value is positive. The only quadrant fill that qualification is Quadrant 1.

The third quadrant.

1st quadrant is +x and +y.

The tangent function is equal to the sine divided by the cosine. In quadrant III, both sin and cos are negative - and a negative divided by another negative is positive. Thus it follows that the tangent is positive in QIII.

Since theta is in the second quadrant, sin(theta) is positive. sin2(theta) = 1 - cos2(theta) = 0.803 So sin(theta) = +sqrt(0.803) = 0.896.

Quadrant I: x positive, y positive. Quadrant II: x negative, y positive. Quadrant III: x negative, y negative. Quadrant II: x positive, y negative.

There's a mnemonic for this: All Students Take Calculus. Starting in the first quadrant, and moving counterclockwise until the last, give each quadrant the first letter of thos words in order. A represents all 3, s represents sine, t represents tangent, and c represents cosine. If the letter appears in a quadrant, it is positive there. If not, it is negative there.In quadrant 2, only sine is positive.

Assuming sin equals 0.3237, the angle is in quadrant I.

The coordinates must be as follows: First quadrant: positive, positive Second quadrant: negative, positive Third quadrant: negative, negative Fourth quadrant: positive, negative

That would be Quadrant I

That's Quadrant - I .

Quadrant I: Top Right: x positive, y positive Quadrant II: Top Left: x negative, y positive Quadrant III: Bottom Left: x negative, y negative Quadrant IV: Bottom Right: x positive, y negative