AB=(4−(−1)2+(−3−9)2=147=12.12CD=(−1−6)2+(5−(−4)2=38=6.16The diagram shows the points A(0,−1),B(p,p) and C(p,q).(a) Given that the length of AB is 5 units, find the value of p.(b) Given that angle BAC= angle BCA, find the value of q.
Q. AB=(4−(−1)2+(−3−9)2=147=12.12CD=(−1−6)2+(5−(−4)2=38=6.16The diagram shows the points A(0,−1),B(p,p) and C(p,q).(a) Given that the length of AB is 5 units, find the value of p.(b) Given that angle BAC= angle BCA, find the value of q.
Calculate AB length: Calculate the length of AB using the coordinates of A and B.AB=(p−0)2+(p−(−1))2Set AB equal to 5 units and solve for p.5=p2+(p+1)2
Set AB to 5 units: Square both sides to remove the square root.25=p2+p2+2p+1Combine like terms.25=2p2+2p+1
Square both sides: Subtract 25 from both sides to set the equation to zero.0=2p2+2p−24
Subtract 25: Divide the entire equation by 2 to simplify.0=p2+p−12
Divide by 2: Factor the quadratic equation.(p+4)(p−3)=0
Factor quadratic equation: Set each factor equal to zero and solve for p.p+4=0 or p−3=0p=−4 or p=3
Solve for p: Since p is a coordinate, it cannot be negative in this context.p=3
Use angle BAC: Use the fact that angle BAC=angleBCA to find q.Since triangle ABC is isosceles, AC=BC.Use the coordinates of A,B, and C to write the expressions for AC and BC.AC=(p−0)2+(q−(−1))2BC=(p−p)2+(q−p)2
Substitute p=3: Substitute p=3 into the expressions for AC and BC.AC=(3−0)2+(q−(−1))2BC=(3−3)2+(q−3)2
Simplify AC and BC: Simplify the expressions for AC and BC.AC = 9+(q+1)2BC = 0+(q−3)2
Set AC=BC: Set AC equal to BC and solve for q.9+(q+1)2=(q−3)2Square both sides to remove the square roots.9+(q+1)2=(q−3)2
Expand squared terms: Expand the squared terms. 9+q2+2q+1=q2−6q+9
Combine like terms: Combine like terms and solve for q.10+2q=−6q+98q=−1q=−81
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