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2 years ago

What is the answer for question 1 and how

Mathematics

2 answers:

Evgesh-ka [11]2 years ago

8 0

CAB= 180-42= 138/2= 69° as base angles of an isosceles triangle are equal
CAO= 90 as radius meets the tangent at 90°
OAB = 90-68= 21°
AOB= 180-(21+21)
=180-42= 138°
a²= b²+c²-2bcCosA
AB²= 7²+7²-2x7x7Cos138
AB²= 170.8281929
AB= √170.8281929
AB= 13.07012597cm
Or 13.1 to 3sf

quester [9]2 years ago

4 0

Step-by-step explanation:

ABC is an isoceles triangle (both legs are equally long). and AB is its baseline.

OC is now a median for ABC splitting the angle at C and AB in half.

so, we have 2 right-angled triangles : OAC and OBC.

the half-angles at C are 42/2 = 21°.

the angles at A and B are 90°.

and the half-angles at O are 180 - 90 - 21 = 69°.

remember that the sum of all angles in a triangle must always be 180°.

AB are the heights of both of these triangles.

the single height is sin(69)×7 = 6.535062985... cm

and so,

AB = 2× height = 13.07012597... cm.

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2. B

Step-by-step explanation:

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points B, C and D;
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Question 20: Please help what are sin x and cos x?

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Answer:

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Step-by-step explanation:

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3 years ago

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irina1246 [14]

Answer:

$y=(x+12)^2\\$

Step-by-step explanation:

To write a quadratic equation into binomial form we can compare the equation into the completing square form of a quadratic equation like this ,

$y=a(x-h)^2+k$

now since,

$y=x^2+24x+144$

we can equate both the equations from left hand side to right hand side like this,

$x^2+24x+144=a(x-h)^2+k\\$

now we solve,

$x^2+24x+144=a(x-h)^2+k\\x^2+24x+144=a((x)^2-2(x)(h)+(h)^2)+k\\x^2+24x+144=a(x^2-2hx+h^2)+k\\x^2+24x+144=ax^2-2ahx+ah^2+k\\$

now we compare the coefficients of x^2:

$1 = a\\$

now we compare the coefficients of x :

$24=-2ah\\24=-2(1)h\\24=-2h\\\frac{24}{-2}=h\\-12=h\\$

now we compare the constants , (constants are the letters which are not associated with any variable in this case the variable is x)

$144 = ah^2+k\\144=(1)(-12)^2+k\\144=(1)(144)+k\\144=144+k\\144-144=k\\0=k\\$

so now the value we got all the values for the completing square form we plug those in , a = 1 , h = -12 , k = 0 ,

$y=a(x-h)^2+k\\y=1(x-(-12))^2+0\\y=(x+12)^2\\$

this is the square of a binomial, if you want to verify if we expands this formula by the formula of (a + b)^2 we would get the same result. Thus this is the correct answer.

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