Answer:
for quadratic equation 1
y^2-10y+21=0
Step-by-step explanation:
y^2-7y-3y+21=0
y(y-7)-3(y-7)=0
(y-7)(y-3)=0
y-7=0,y-3=0
y=7,y=3
y=(3,7)
for quadratic equation 2
16p^2-8p+1=0
16p^2-4p-4p+1=0
4p(4p-1)-1(4p-1)=0
(4p-1)twice=0
4p-1=0,4p-1=0
4p=1
p=1/4 twice
for quadratic equation 3
x^2-400=0
x^2=400
x=√400
x=20
for quadratic equation 4
-16m^2-8m-1=0
multiply the equation by -
16m^2+8m+1=0
16m^2+4m+4m+1=0
4m(4m+1)1(4m+1)=0
4m+1=0 twice
m=-1/4 twice
for quadratic equation 5
-3n^2+75=0
divide both side by -3
-3n^2/-3=-75/-3
n^2=25
n=√25
n=5
<span>The exact solution of cos (17</span>π<span>/6) is as follows:
First change the angle into degrees.
17(</span>π/6) (180°/π) = 510°
Then we calculate the cosine of the angle above and it as follows:
cos 510° = -(√3)/2
Hope this answers the question. Have a nice day.
Answer:
D.) It has rotational symmetry with an angle of rotation of 90 degrees.
Step-by-step explanation:
i) the shape shown in the figure has reflectional symmetry with four lines of symmetry. There are four lines of symmetry such that each line when drawn divides the shape into two exact halves such that if each half were too be folded across the line of symmetry it would produce the other half exactly.
Therefore Option A.) and Option B.) are not true
ii) It has point symmetry which means if the shape is rotated by 180 degrees the shape does not change. Therefore Option C.) is not true.
iii) the shape has rotational symmetry because if the shape is rotated though any between 0 degrees and 360 degrees the shape appears to be unchanged.
Therefore the correct options are
D.) It has rotational symmetry with an angle of rotation of 90 degrees.
The answer is 9(3+x)
My work is in the attached image
