3.Find the cosine of the angle in standard position in which the terminal side passes through the point (-5,12)
A) 5/12
B)--5/12
C)12/13
D)-5/13
4. Find the sine of the angel in standard position in which the terminal side passes through the point (-8,-15)
A)8/15
B)-8/17
C)15/17
D)-15/17
Trigonometry ? 2 Questions?
2016-07-12 10:49 am
回答 (1)
2016-07-12 11:25 am
3.
Δx = -5
Δy = 12
√[(Δx)² + (Δy)²]
= √[(-5)² + (12)²]
= √169
= 13
cos(the angle)
= Δx / √[(Δx)² + (Δy)²]
= -5/13
...... The answer is : D) -5/13
====
4.
Δx = -8
Δy = -15
√[(Δx)² + (Δy)²]
= √[(-8)² + (15)²]
= √289
= 17
sin(the angle)
= Δy / √[(Δx)² + (Δy)²]
= -15/17
...... The answer is : D) -15/17
Δx = -5
Δy = 12
√[(Δx)² + (Δy)²]
= √[(-5)² + (12)²]
= √169
= 13
cos(the angle)
= Δx / √[(Δx)² + (Δy)²]
= -5/13
...... The answer is : D) -5/13
====
4.
Δx = -8
Δy = -15
√[(Δx)² + (Δy)²]
= √[(-8)² + (15)²]
= √289
= 17
sin(the angle)
= Δy / √[(Δx)² + (Δy)²]
= -15/17
...... The answer is : D) -15/17
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