The schools start soon. Here is a quiz: prove the sum of two consequent triangular numbers is a square number. Triangular numbers are the sums of equilength triangles, i.e. 1, 3 (=1+2), 6 (=3+3), 10 (=6+4), etc. (*)
The colors of leaves change from green, which is the color of chlorophylls. Chlorophylls is decomposed in fall to colorless tetrapyrroles and that changes the color.
The decomposition shows the color of cartenoids such as xanthophylls that are hidden under the presence of chlorophylls, which are green. Then red anthocyanins are synthesized when chlorophylls are decomposed and that shows the red color. The phosphates that decompose sugers moves from leaves to stems in fall, which signals the synthesis of anthocyanins.
The input levels of CMOS is relative to the overall power supply voltage whereas the threshold voltage of TTL logic is absolute. This is due to the nature of CMOS complementary logic. The input threshold of a CMOS logic typically ranges from .8*Vcc (H->L) and .2*Vcc (L->H). The TTL logic threshold ranges from .8 to 2 to 5 V.
(*) The answer: sum = n(n-1)/2+n(n+1)/2
The colors of leaves change from green, which is the color of chlorophylls. Chlorophylls is decomposed in fall to colorless tetrapyrroles and that changes the color.
The decomposition shows the color of cartenoids such as xanthophylls that are hidden under the presence of chlorophylls, which are green. Then red anthocyanins are synthesized when chlorophylls are decomposed and that shows the red color. The phosphates that decompose sugers moves from leaves to stems in fall, which signals the synthesis of anthocyanins.
The input levels of CMOS is relative to the overall power supply voltage whereas the threshold voltage of TTL logic is absolute. This is due to the nature of CMOS complementary logic. The input threshold of a CMOS logic typically ranges from .8*Vcc (H->L) and .2*Vcc (L->H). The TTL logic threshold ranges from .8 to 2 to 5 V.
(*) The answer: sum = n(n-1)/2+n(n+1)/2