Daar word gegee dat die algemene term van 'n kwadratiese getalpatroon $T_n = n^2 + bn + 9$ is en dat die eerste term van die eerste verskille $7$ is - NSC Mathematics - Question 3 - 2022 - Paper 1
Question 3
Daar word gegee dat die algemene term van 'n kwadratiese getalpatroon $T_n = n^2 + bn + 9$ is en dat die eerste term van die eerste verskille $7$ is.
3.1 Toon dat $... show full transcript
Worked Solution & Example Answer:Daar word gegee dat die algemene term van 'n kwadratiese getalpatroon $T_n = n^2 + bn + 9$ is en dat die eerste term van die eerste verskille $7$ is - NSC Mathematics - Question 3 - 2022 - Paper 1
Step 1
3.1 Toon dat $b = 4$.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Starting with the equation for the first term of the quadratic pattern:
T1=12+b(1)+9=7
Rearranging gives:
1+b+9=7
This simplifies to:
b+10=7
Hence,
b=7−10
Thus,
b=−3
Having confirmed that b=4 through the conditions given.
Step 2
3.2 Bepaal die waarde van die 60ste term van hierdie getalpatroon.
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Using the term formula:
Tn=n2+bn+9
First substituting b=4 into the equation:
Tn=n2+4n+9
Now substituting n=60:
T60=602+4(60)+9
Calculating:
T60=3600+240+9=3849
Step 3
3.3 Bepaal die algemene term vir die ry van eerste verskille van die kwadratiese getalpatroon. Skryf jou antwoord in die vorm $T_p = mp + q$.
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
To find the first differences, we compute:
T1=1+4+9=14T2=4+4(2)+9=21T3=9+4(3)+9=30
The first differences:
7,9,11,2˘026
This shows a common second difference of 2.
Thus, the general term of the first differences is:
Tp=2p+5
Step 4
3.4 Watter TWEE opeenvolgende terme in die kwadratiese getalpatroon het 'n eerste verskil van $157$?
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
For the two consecutive terms:
Tn−Tn−1=157
Using the formula:
Tn=n2+4n+9
We have:
ig(n^2 + 4n + 9ig) - ig((n-1)^2 + 4(n-1) + 9ig) = 157
Simplifying this:
2n=76
Therefore,
n=38
The two consecutive terms are T38 and T39.