Find the value of C in a triangle where a = 6, b = 8, and c = 12.

Mathematics

1 answer:

ELEN [110]3 years ago

7 0

Answer: 117°

<u>Step-by-step explanation:</u>

Use the Law of Cosines:

c² = a² + b² - 2ab · cos C

12² = 6² + 8² - 2(6)(8)(cos C)

144 = 36 + 64 - 96 cos C

144 = 100 - 96 cos C

44 = -96 cos C

$-\dfrac{44}{96}=cosC\\\\\\cos^{-1}\bigg(-\dfrac{44}{96}\bigg)=C$

117° = C

You might be interested in

Example 3: Seven sheets of coloured paper are on Shannon's desk. If there are four sheets

hoa [83]

Answer: she can stack the paper 57 ways

Step-by-step explanation:

3 0

2 years ago

-5x+y=-2<br> -3x+6y=-12<br> Solve by using substitution.

KIM [24]

-5x+y=-2
y=5x-2

-3x+6(5x-2)=-12
-3x+30x-12=-12
27x-12=-12
27x= 0
x= (0/27)
x=0
-5(0)+y=-2
0+y=-2
y=-2

4 0

3 years ago

What is the solution-2|2.2x-3.3|=-6.6

mylen [45]

$Solution, solve\:for\:x,\:-2\left|2.2x-3.3\right|=-6.6\quad :\quad x=0\quad \mathrm{or}\quad \:x=3$

$Steps:$

$-2\left|2.2x-3.3\right|=-6.6$

$\mathrm{Divide\:both\:sides\:by\:}-2,\\\frac{-2\left|2.2x-3.3\right|}{-2}=\frac{-6.6}{-2}$

$\mathrm{Simplify},\\\left|2.2x-3.3\right|=3.3$

$|f\left(x\right)|=a\quad \Rightarrow \:f\left(x\right)=-a\quad \mathrm{or}\quad \:f\left(x\right)=a,\\2.2x-3.3=-3.3\quad \quad \mathrm{or}\quad \:\quad \:2.2x-3.3=3.3$

$2.2x-3.3=-3.3,\\\mathrm{Add\:}3.3\mathrm{\:to\:both\:sides},\\2.2x-3.3+3.3=-3.3+3.3,\\\mathrm{Refine},\\2.2x=0,\\\mathrm{Multiply\:both\:sides\:by\:}10,\\.2x\cdot \:10=0\cdot \:10,\\\mathrm{Refine},\\22x=0,\\\mathrm{Divide\:both\:sides\:by\:}22,\\\frac{22x}{22}=\frac{0}{22},\\\mathrm{Simplify},\\x=0$

$2.2x-3.3=3.3,\\\mathrm{Multiply\:both\:sides\:by\:}10,\\2.2x\cdot \:10-3.3\cdot \:10=3.3\cdot \:10,\\\mathrm{Refine},\\22x-33=33,\\\mathrm{Add\:}33\mathrm{\:to\:both\:sides},\\22x-33+33=33+33,\\\mathrm{Simplify},\\22x=66,\\\mathrm{Divide\:both\:sides\:by\:}22,\\\frac{22x}{22}=\frac{66}{22},\\\mathrm{Simplify},\\x=3$