HPreCalc Chapter 6 Part 1 Test Flashcards Preview

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Flashcards in HPreCalc Chapter 6 Part 1 Test Deck (25):
1

What is the alternative form of the law of cosines

CosA=b^2+c^2-a^2/2bc

2

Always use ______ decimals for problems with multiple steps

Unrounded

3

Why can't you use the law of sines to find an obtuse angle
What should you do to avoid making this mistake

Law of sines has a domain that will make the angle either right or acute
Use law of cosines to find biggest angle first

4

When using Heron's formula, look for __________ and __________

Perfect squares and repeated factors

5

If you have 45 in Heron's formula, separate it into __ and ___

9 and 5 (take out a 3)

6

When finding a bearing in a triangle, start N or S. You can tell by seeing which one is closest to a ___ of that triangle

Side

7

When you are given three sides of a triangle, you use the Law of ___ to find the three angles of the triangle

Cosines

8

When you are given two angles and any side of a triangle, you use the law of ____ to solve the triangle

Sines

9

The law of cosines can be used to establish a formula for finding the area of a triangle;e called _____ ______ formula

Heron's Area

10

When do you use law of cosines

SSS
SAS

11

When do you use law of sines

ASA, AAS, SSA

12

When is it not possible to use law of sines or law of cosines

AAA

13

What is ambiguous case
Explain

SSA
There can (possibly) be two triangles or even no triangles.
Find the height and decide

14

When you can make two triangles using ambiguous case, how do you find the second

Make the other angle its supplement (should be obtuse). Keep the two side lengths the same and solve

15

Oblique means

Not right or isosceles

16

What is the law of sines

A/sinA=B/sinB=C/sinC

17

Always check that the largest ____ matches up with the largest ____-

Angle, side

18

Obtuse oblique triangles can either have ___ or ___ triangles
How can you tell

One, no
The side opposite the largest angle must be the largest side

19

What is the area of an oblique triangle
When can this equation be used

Area=1/2bcsinA
SAS

20

An _____ triangle is a triangle that has no right angle

Oblique

21

For triangle ABC, the law of sines is a/sinA=_______=c/sinC

B/sinB

22

Two ____ and one ____ determine a unique triangle

Angles, side

23

The area of an oblique triangle is 1/2bcsinA=1/2absinC=_______

1/2acsinB

24

Given A=36 degrees and a=5
What is one possible combination for one solution, two solutions, and no solution

One solution- 5 is greater than or equal to b, b=5sin36
Two solutions- 5 is less than B and B is less than 5/sin36
No solution- b is greater than 5/sin36

25

What is the law of cosines

A^2=b^2+c^2-2bccosA