What is the cosine of 135 degrees?

Mathematics

2 answers:

Varvara68 [4.7K]2 years ago

7 0

$cos(180^0- \alpha )=-cos \alpha \\ \\ cos135^0=cos(180^0-45^0)=-cos45^0=- \frac{ \sqrt{2} }{2}$

belka [17]2 years ago

3 0

$cos135^o=cos(90^o+45^o)=-sin45^o=-\frac{\sqrt2}{2}\\\\reduction\ formulas:\ cos(90^o+\alpha)=-sin\alpha$

You might be interested in

Write an equation to represent the following statement.<br> 24 is 4 times as great as k.

Artyom0805 [142]

Answer:

24 x 4 = k x 4

Step-by-step explanation:

8 0

2 years ago

Evaluate the expression for the given value of the variables.

zzz [600]

For every c substitute 4 and for every d substitute -2

c=4
d=-2

6c + 5d - 4c - 3d + 3c - 6d

= 6(4)+ 5(-2)- 4(4)- 3(-2)+ 3(4)- 6(-2)

=24+(-10)-16-(-6)+12-(-12)

=24-10-16+6+12+12

=28

7 0

2 years ago

What is the perimeter of a polygon with vertices at (−2, 1) , (−2, 4) , (2, 7) , (6, 4) , and (6, 1) ?

alekssr [168]

First we need the distances of the sides of the polygon, because perimeter = sum of all sides.
$d = \sqrt{{(y2 - y1)}^{2} + {(x2 - x1)}^{2} }$
$d1 = \sqrt{{(1 - 4)}^{2} + {( - 2 - - 2)}^{2} } \\ = \sqrt{{(- 3)}^{2} + {(0)}^{2} } = \sqrt{9} \: = 3$
$d2 = \sqrt{{(4 - 7)}^{2} + {( - 2 - 2)}^{2} } \\ = \sqrt{{(- 3)}^{2} + {( -4)}^{2} } = \sqrt{9 + 16} \\ = \sqrt{25} \: = 5$
$d3 \: = \sqrt{{(7 - 4)}^{2} + {(2 - 6)}^{2} } \\ = \sqrt{{(3)}^{2} + {( - 4)}^{2} } = \sqrt{9 + 16} \\ = \sqrt{25} \: = 5$
$d4 = \sqrt{{(4 - 1)}^{2} + {(6 - 6)}^{2} } \\ = \sqrt{ {(3)}^{2} + {(0)}^{2} } = \sqrt{9} \: = 3$
$d5 = \sqrt{{(1 - 1)}^{2} + {(-2 - 6)}^{2} } \\ = \sqrt{ {(0)}^{2} + {( - 4)}^{2}} = \sqrt{16} \: = 4$
Now, we add all sides for the perimeter:
p = d1 + d2 + d3 + d4 + d5
p = 3+5+5+3+4 = 20 units

5 0

2 years ago

Read 2 more answers

Help me please !!! I DONT KNOW WHAT TO PUT PLS HELP ME

Genrish500 [490]

I believe it is congruent

7 0

2 years ago

Add (2x+5) + (3x-7)<br> plsssssss SBUIAXSBADJASN

MArishka [77]

2x+3x= 5x
5-7= -2

so its 5x-2 since all like terms are added

6 0

2 years ago