Question

20.Find the value of sin 30" # cos 60"
SECTIO-B
Question numbers 21 to 26 carry 2 marks each.
21. Find the sum of A.P: 2,7, 12.....to 10 terms.
22. Find the value of 9sec A-9 tan A.
23. For what value of K does kx(x - 2)+6=0 have equal roots.
24. Which term of A.P. 3,8,13,18 ........... Is 78.
25. Find a quadratic polynomlals whose sum and product of its zero
26. Solve the following pair of equations
3x - y =7
2x + 5y +10​

Answer 1

Answer:

20. sin30°= 1/2

cos 30°= 1/2

21. the sum of AP to its 10th term is

a= 2

d=7-2=5

n=10

sum of AP= Sn= n/2[2a+(n-1)d]

=10/2[2×2+(10-1)5]

=5(4+45)

=5×49=245

22.9(secA-tanA)

= 9(1/cosA - sinA/cosA)

= 9(1-sinA/cosA)

= 9(cosA/cosA) here cos A will cancel each other

= 9 ( is the answer)

HOPE THIS ANSWER WILL HELP YOU SOMEHOW!!!