# In ΔABC, sin 2A+sin 2B+sin 2C/sin A+ sin B+sin C=

1.  4 sin A/2sin B/2 sin C/2

2.  4cos A/2 cos B/2 cos C/2

3.  8 sin A/2 sin B/2 sin C/2

4.  1+ 4sin A/2 sin B/2 sin C/2

4

8 sin A/2 sin B/2 sin C/2

Explanation :
No Explanation available for this question

# If A+B+C= 1800 then cos A+cos B+ cos C=

1.  1+4sin A/2sin B/2 sin C/2

2.   1+4 cos A/2cos B/2sin C/2

3.  1+ 4 cos A/2 cos B/2 cos C/2

4.  1+ 4cos A/2sin B/2 cos C/2

4

1+4sin A/2sin B/2 sin C/2

Explanation :
No Explanation available for this question

# The numbers an=6n-5n for n=1,2,3… when divided by 25 leave the remainder

1.  9

2.  7

3.  3

4.  1

4

1

Explanation :
No Explanation available for this question

# If A+B+C= 1800 then cos A- cos B+cos C=

1.  -1+4sin A/2sin B/2 sin C/2

2.  -1+4 cos A/2cos B/2sin C/2

3.  -1+ 4 cos A/2 cos B/2 cos C/2

4.  -1+ 4cos A/2sin B/2 cos C/2

4

-1+ 4cos A/2sin B/2 cos C/2

Explanation :
No Explanation available for this question

# In ΔABC, (sin 2A+ sin 2B+sin 2C)/(cos A+ cos B+ cos C-1)=

1.  4 cos A/2 cos B/2 cos C/2

2.  4 sin A/2 sin B/2 sin C/2

3.  8 cos A/2 cos B/2 cos C/2

4.  1+ 4 sin A/2 sin B/2 sin C/2

4

8 cos A/2 cos B/2 cos C/2

Explanation :
No Explanation available for this question

# I: 1+3+5+7+…..+(2n-1)=n2 II: 2+4+6+8+….+2n=n2

1.  Only I is true

2.  Only II is true

3.  both I and II are true

4.  Neither I nor II are true

4

Only I is true

Explanation :
No Explanation available for this question

# If A+B+C= 1800 then cos2 A+ cos 2 B+cos2 C=

1.  1-2 cos A cos B cos C

2.  1+2 cos A cos B cos C

3.  1+cos A cos B cos C

4.  1-cos A cos B cos C

4

1-2 cos A cos B cos C

Explanation :
No Explanation available for this question

# I: 1+3+6+10+… nterms=n(n+1)/2 II: 1+3+7+15+…. Nterms=2n+1-n-2

1.  Only I is true

2.  Only II is true

3.  both I and II are true

4.  Neither I nor II are true

4

Only II is true

Explanation :
No Explanation available for this question

# If A+B+C= 1800 then cos2 A+ cos 2 B - cos2 C=

1.  1- 2 sin A sin B cos C

2.  1- 2 sin A cos B sin C

3.  1- 2 cos A cos B cos C

4.  1- 2 sin A sin B sin C

4

1- 2 sin A sin B cos C

Explanation :
No Explanation available for this question

# If A+B+C= 1800 then sin2 A/2+ sin 2 B/2 - sin2 C/2=

1.  1- 2 sin A/2 sin B/2 sin C/2

2.  1- 2 cos A/2 cos B/2 cos C/2

3.  1- 2 cos A/2cos B/2 sin C/2

4.  1- 2 sin A/2cos B/2 sin C/2

4