Question

19. The product 3/4, 2/5 and 25/3 is (b) 2/5 (c) 3/5 la) 5/2 (d) 5/3​

Answer 1

Answer:

(x2+y2)2=xy

x4+2x2y2+y4−xy=0

Differentiating w.r.t x, 

4x3+2[x2.2y

Answer 2

Answer:

Given: Coordinates of Point A(1,3),B(−1,0) and C(4,0)

Construction: Drop a perpendicular from A on x− axis, which meets x-axis at D≡(1,0)

Now in ΔADC,AD=3,DC=3

Area of ΔADC=21×DC×AD

=21×3×3=29 cm2

Now in ΔADB,AD=3,DB=2

Area of ΔADB=21×DB×AD

=21×2×3=3 cm2

Area of ΔABC= Ara of ΔADC+ Area of ΔABD

=29+3=215=7.5 cm2