<h3>
Answer: Choice 2) sin(B) = cos(90-B)</h3>
Explanation:
The rule is that
sin(A) = cos(B)
if and only if A+B = 90.
Solving for A gets A = 90-B
So we end up with
sin(90-B) = cos(B)
which is the same as
cos(B) = sin(90-B)
Answer:
Step-by-step explanation:
13.
x³-x²-x-2=0
x³-2x²+x^2-2x+x-2=0
x²(x-2)+x(x-2)+1(x-2)=0
(x-2)(x²+x+1)=0
x-2=0,x=2
x²+x+1=0
<em>12.</em>
<em>3x^4-11x³+15x²-9x+2=0</em>
<em>\[3x^4-3x^3-8x^3+8x²+7x²-7x-2x+2=0\]</em>
<em>3x³(x-1)-8x²(x-1)+7x(x-1)-2(x-1)=0</em>
<em>(x-1)[3x³-8x²+7x-2]=0</em>
<em>x-1=0,gives x=1</em>
<em>3x³-8x²+7x-2=0</em>
<em>3x³-3x²-5x²+5x+2x-2=0</em>
<em>3x²(x-1)-5x(x-1)+2(x-1)=0</em>
<em>(x-1)(3x²-5x+2)=0</em>
<em>x-1=0,gives x=1</em>
<em>3x²-5x+2=0</em>
<em>3x²-3x-2x+2=0</em>
<em>3x(x-1)-2(x-1)=0</em>
<em>(x-1)(3x-2)=0</em>
<em>x-1=0,gives x=1</em>
<em>3x-2=0, gives x=2/3</em>
<em>so roots are 2/3,1,1,1</em>
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Answer:
A Solution is a value we can put in place of a variable (such as x) that makes the equation true.
Step-by-step explanation:
We know that Sum of Angles in a Triangle is Equal to 180°
Here EBF is a Triangle
⇒ m∠EBF + m∠BEF + m∠EFB = 180°
⇒ 60° + 40° + m∠EFB = 180°
⇒ 100° + m∠EFB = 180°
⇒ m∠EFB = 180° - 100°
⇒ m∠EFB = 80°
As Line m and Line p are Parallel Lines :
Alternate Interior Angles are Equal, here Alternate Interior Angles are m∠BEF and m∠ABE
⇒ m∠BEF = m∠ABE
⇒ m∠ABE = 40°
We know that Vertically Opposite Angles are Equal, Here m∠GFI and m∠EFB are Vertically Opposite Angles.
⇒ m∠GFI = m∠EFB
⇒ m∠GFI = 80°
We can notice that m∠DEB and m∠BEF form a Linear Pair
⇒ m∠DEB + m∠BEF = 180°
⇒ m∠DEB + 40° = 180°
⇒ m∠DEB = 180° - 40°
⇒ m∠DEB = 140°
We can notice that Sum of Angles m∠CBF and m∠EBF and m∠ABE is 180°
⇒ m∠CBF + m∠EBF + m∠ABE = 180°
⇒ m∠CBF + 60° + 40° = 180°
⇒ m∠CBF + 100° = 180°
⇒ m∠CBF = 180° - 100°
⇒ m∠CBF = 80°
We can notice that m∠BFG and m∠EFB form a Linear Pair
⇒ m∠BFG + m∠EFB = 180°
⇒ m∠BFG + 80° = 180°
⇒ m∠BFG = 180° - 80°
⇒ m∠BFG = 100°
We know that Vertically Opposite Angles are Equal, Here m∠BFG and m∠IFE are Vertically Opposite Angles.
⇒ m∠BFG = m∠IFE
⇒ m∠IFE = 100°
