TG EAMCET 4 May 2025 Shift 1 Paper

Let side of cube be a.
Let coordinates of vertices of cube are shown as in figure.
Ratio direction ratio of line AQ is a:a:−a
Ratio of direction ratio of line BR is a:−a:a.
cos‌α=‌

|a2−a2−a2|

√3a×√3a

=‌

1

3

Let ratio of direction ratio of line BD be a:−a:0
‌cos‌β=‌

a2+a2

√3a×√2a

=√‌

2

3

⇒‌‌cos‌α+cos2β=‌

1

3

+‌

2

3

=1