Radians ch 5 Flashcards Preview

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Flashcards in Radians ch 5 Deck (12)
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1
Q

What is the formula for arc length?

A

Theta x radius (when theta is in radians mode)

2
Q

What is the difference between a major arc and a minor arc?

A

A major arc has the majority of the angle round the point at the centre of the circle whereas the minor arc has a smaller angle.

3
Q

What is the difference between a sector and a segment?

A

Sector is the area enclosed by two radii.

Segment is the area enclosed by a chord and perimeter.

4
Q

What is the formula for area of a sector?

A

1/2r^2 x theeta.

5
Q

How do you work out the area of a segment?

A

Area of sector - area of triangle.

6
Q

Why does the small angle approximations work for sin?

A

Because for very small values of theta the sin curve is very similar to the y=theeta curve.

7
Q

What is the small angle approximation for sin?

A

When theta is small and measured in radians, sintheta is approx theta

8
Q

Why do the small angle approximations work for cos?

A

Because for small values of theta, cos curve tends to 1-1/2theta^2

9
Q

What is the small angle approximation for cos?

A

Costheeta is approx 1-1/2theeta^2

10
Q

why does the small angle approximations work for tan?

A

Because for very small values of theta, y=theeta tends towards tantheeta

11
Q

How would you deal with a cos4theeta in small angle approximation?

A

Sub in 4 theta for theta in cos.

12
Q

How would you state the approximate value of 2theta^2+7theta-1?

A

Take all the theta as 0 or negligible so answer would be -1